Microsoft Edge users this week may have noticed their browser updating to version 138.0.3351.77, a release aimed at resolving a frustrating audio playback issue impacting specific websites. This seemingly minor update drew widespread attention—not only because of the browser glitch it addressed but also due to Microsoft’s method of temporarily rolling back a recent, unspecified change in Edge to offer immediate relief. The episode underscores both the power and pitfalls of maintaining a modern web browser and highlights how tightly interwoven the browser ecosystem is with rapidly evolving web technologies and third-party libraries.
In its official release notes, Microsoft revealed that the problematic bug disrupted audio when playing video content encoded with the AAC codec on certain websites. Rather than a superficial compatibility hiccup, the root cause was traced to outdated versions of HLS.js—a widely-used JavaScript library that facilitates HTTP Live Streaming (HLS) directly within browsers.
HLS.js has become the go-to for many web developers who serve live and on-demand streaming content via HLS, owing to its flexibility and browser compatibility. When a browser or library introduces subtle changes, the ripple effect can be significant, particularly when widespread standards like AAC audio or HLS.js are involved. According to Microsoft, the proper resolution lies in web developers updating their applications to newer releases of HLS.js, addressing the underlying incompatibilities. However, such ecosystem-wide updates take time, and with many high-traffic websites relying on web standards, Microsoft opted for a temporary workaround: rolling back a recent change in Edge itself to restore reliable audio playback.
It’s worth noting that Microsoft has not publicly specified exactly which Edge change was undone. This lack of transparency is common when divulging specifics might inadvertently reveal security-sensitive implementation details or implicate third-party dependencies not yet fixed. Still, it makes independent verification of the precise technical adjustment challenging.
Through monitoring technical forums and user reports, it’s clear that the bug affected not just obscure platforms but also popular streaming services and corporate video portals. While Microsoft’s fast response was generally commended, some users expressed frustration at recurrent regression bugs following Edge updates—a growing concern as browser release cadences accelerate and internal changes multiply.
From a strategic and technical perspective, this episode exemplifies several recurring realities of software engineering at scale:
Further, Microsoft claims the overall browser is now 40% faster compared to previous iterations, a leap that, if borne out by independent benchmarking, potentially leapfrogs Edge ahead of its Chromium-based rivals—including Google Chrome—in raw interface responsiveness. This is a notable achievement, particularly as the browser market becomes ever more competitive on speed, energy efficiency, and perceived fluidity.
To place this figure in context, major browser vendors typically boast performance improvements in the single or low double-digit percentages, not 40%. While Microsoft’s claim refers specifically to UI responsiveness under certain conditions (such as navigating to the Settings page), third-party testers including sites like Tom’s Hardware and PCWorld have reported substantial improvements but sometimes caution that real-world speed gains will vary based on system configuration and usage patterns. That said, even a fraction of such an advance can be transformative in day-to-day use, especially for enterprise deployments managing fleets of devices.
For example, instead of simply showing instances of a queried keyword, the enhanced Find on Page tool could now summarize document sections, highlight relevant paragraphs, or even answer questions related to page content. For knowledge workers wrestling with dense documentation or lengthy reports, AI-assisted tools like this promise time savings and cognitive relief.
This integration exemplifies Microsoft’s broader strategy to weave generative AI and digital assistants into every productivity touchpoint—including the browser. As Google and others race to embed AI into their own products, the line between conventional browser features and AI-enhanced workflows continues to blur. For IT administrators, the advent of Copilot inside Edge raises new points of consideration around privacy, data governance, and user training.
Nevertheless, security-conscious users and IT admins should closely monitor upcoming releases, as patches addressing discovered vulnerabilities are likely to follow in quick succession, particularly after a rapid bugfix update like this one.
Web developers, particularly those managing large content libraries or enterprise streaming portals, face a more nuanced challenge. While the immediate crisis is resolved, best practices—such as regularly updating third-party libraries like HLS.js and validating against all major browsers—remain critically important. Microsoft’s experience is a clear signal to monitor not only the core browser changelogs but also the project health and release cycles of dependencies like HLS.js.
IT administrators, meanwhile, should verify that fleet-wide Edge distributions receive these updates promptly, especially where media playback is part of core workflows. They should also track emerging Edge features—especially Copilot-powered enhancements—to assess potential impacts on compliance, privacy regimes, and internal support needs.
For Microsoft, extending the appeal of Edge to both consumers and business users is paramount. Integration with Copilot and deeper ties to Microsoft 365 ecosystems are intended to entrench Edge as the default browser for the hybrid workforce—not merely as an alternative to Chrome, but as a productivity suite in its own right.
Yet, as evidenced by the recent rollback, such ambition is accompanied by new risks: only through relentless testing, communication, and cross-ecosystem collaboration can browser innovation progress without alienating users and developers through disruptive regressions.
For all its ambitions, however, the Edge team must also reckon with the realities of an ecosystem in constant flux. Maintaining robust, user-centric performance while adopting cutting-edge features and juggling third-party dependencies is no easy task.
Ultimately, Microsoft’s readiness to acknowledge, address, and communicate around issues—while continuing to push the envelope on productivity and speed—remains the best barometer for Edge’s long-term prospects. As the browser wars enter another decade, adaptability, transparency, and user trust will be as valuable as any new feature or benchmark. And as the latest Edge update has made clear, sometimes the quickest path forward is a timely step back.
Source: Neowin Microsoft temporarily removes one Edge change to fix unexpected issues
In its official release notes, Microsoft revealed that the problematic bug disrupted audio when playing video content encoded with the AAC codec on certain websites. Rather than a superficial compatibility hiccup, the root cause was traced to outdated versions of HLS.js—a widely-used JavaScript library that facilitates HTTP Live Streaming (HLS) directly within browsers.HLS.js has become the go-to for many web developers who serve live and on-demand streaming content via HLS, owing to its flexibility and browser compatibility. When a browser or library introduces subtle changes, the ripple effect can be significant, particularly when widespread standards like AAC audio or HLS.js are involved. According to Microsoft, the proper resolution lies in web developers updating their applications to newer releases of HLS.js, addressing the underlying incompatibilities. However, such ecosystem-wide updates take time, and with many high-traffic websites relying on web standards, Microsoft opted for a temporary workaround: rolling back a recent change in Edge itself to restore reliable audio playback.
It’s worth noting that Microsoft has not publicly specified exactly which Edge change was undone. This lack of transparency is common when divulging specifics might inadvertently reveal security-sensitive implementation details or implicate third-party dependencies not yet fixed. Still, it makes independent verification of the precise technical adjustment challenging.
The Severity and Impact of the Bug
For end users, the issue manifested as muted or distorted audio on streaming video platforms—specifically those relying on the older versions of HLS.js and delivering content with AAC audio. Given that AAC is a dominant format for web audio, and HLS.js underpins much of the modern streaming infrastructure, even a seemingly minor incompatibility can have a pronounced impact on user experiences across multiple sites, spanning entertainment, education, and business.Through monitoring technical forums and user reports, it’s clear that the bug affected not just obscure platforms but also popular streaming services and corporate video portals. While Microsoft’s fast response was generally commended, some users expressed frustration at recurrent regression bugs following Edge updates—a growing concern as browser release cadences accelerate and internal changes multiply.
Microsoft’s Workaround: A Temporary Safety Net
The reinstated Edge 138.0.3351.77 update acts as a stopgap, returning browser behavior to a prior state until the larger ecosystem can catch up. By reverting the unidentified change responsible for the audio disruption, Microsoft restored user confidence in Edge's streaming capabilities—at least in the short term.From a strategic and technical perspective, this episode exemplifies several recurring realities of software engineering at scale:
- Third-party dependencies matter: Browsers must interact fluidly with hundreds of libraries—most beyond their direct control. Any change, whether in the browser itself or its web runtime, can break longstanding integrations.
- Rapid fixes > perfect ones (sometimes): When millions of users are impacted, restoring functionality often trumps waiting for all parties in the ecosystem to deploy upgrades.
- Transparency and documentation: While Microsoft’s approach ensured user problems were quickly resolved, their decision not to disclose the specific reverted change limits developer insight and slows long-term learning across the community.
The Broader Context: Edge Performance, UI, and Business Integrations
While this update was laser-focused on the AAC audio issue, Microsoft also used its June communication to highlight broader innovations in Edge. Particularly noteworthy are the following two changes, each aimed at reshaping browser experience and business productivity.WebUI 2.0: Setting New Performance Benchmarks
Microsoft’s recent introduction of WebUI 2.0 represents a foundational overhaul of Edge’s internal settings and management user interface. According to Microsoft, the performance improvements here are dramatic: settings pages now render in less than 300 milliseconds, which is, for all practical purposes, instantaneous from a human perspective.Further, Microsoft claims the overall browser is now 40% faster compared to previous iterations, a leap that, if borne out by independent benchmarking, potentially leapfrogs Edge ahead of its Chromium-based rivals—including Google Chrome—in raw interface responsiveness. This is a notable achievement, particularly as the browser market becomes ever more competitive on speed, energy efficiency, and perceived fluidity.
To place this figure in context, major browser vendors typically boast performance improvements in the single or low double-digit percentages, not 40%. While Microsoft’s claim refers specifically to UI responsiveness under certain conditions (such as navigating to the Settings page), third-party testers including sites like Tom’s Hardware and PCWorld have reported substantial improvements but sometimes caution that real-world speed gains will vary based on system configuration and usage patterns. That said, even a fraction of such an advance can be transformative in day-to-day use, especially for enterprise deployments managing fleets of devices.
Find on Page Meets Copilot Chat: A New Productivity Era
The update also introduces deeper integration between Edge’s “Find on Page” feature (Ctrl + F) and Microsoft 365 Copilot Chat—initially aimed at enterprise users via Edge for Business. In practice, this means that when users search for specific words or phrases within a web page, Copilot Chat can offer intelligent, context-aware suggestions, summaries, and deeper insights by leveraging Microsoft’s AI.For example, instead of simply showing instances of a queried keyword, the enhanced Find on Page tool could now summarize document sections, highlight relevant paragraphs, or even answer questions related to page content. For knowledge workers wrestling with dense documentation or lengthy reports, AI-assisted tools like this promise time savings and cognitive relief.
This integration exemplifies Microsoft’s broader strategy to weave generative AI and digital assistants into every productivity touchpoint—including the browser. As Google and others race to embed AI into their own products, the line between conventional browser features and AI-enhanced workflows continues to blur. For IT administrators, the advent of Copilot inside Edge raises new points of consideration around privacy, data governance, and user training.
Security Updates: Not This Time
Curiously, Edge 138.0.3351.77 does not contain any security fixes or additional feature patches. The focus is laser-sharp: one bugfix, one feature update, and no more. Ordinarily, Edge releases (especially Stable Channel rollouts) coincide with at least a handful of security mitigations, given the browser’s importance as both a first line of defense and a top attack vector. This absence may reflect Microsoft’s internal risk calculations or simply the nature of the rapidly-issued, emergency patch cycle.Nevertheless, security-conscious users and IT admins should closely monitor upcoming releases, as patches addressing discovered vulnerabilities are likely to follow in quick succession, particularly after a rapid bugfix update like this one.
Critical Analysis: Strengths, Weaknesses, and Risks
Microsoft’s handling of this issue, along with ongoing enhancements to Edge, illustrates the formidable challenges and opportunities of developing a major browser in 2025. Several notable strengths and potential risks stand out:Strengths
- Rapid Response: The speed with which Microsoft diagnosed, attributed, and patched the AAC audio issue is commendable. Rolling back the problematic change, even temporarily, minimized user disruption and protected the browser’s reputation in the crucial streaming media space.
- User-Centric Innovation: WebUI 2.0 and Copilot Chat integrations demonstrate that Microsoft is leaning into both performance and productivity—areas of high value for business users and casual consumers alike.
- Communication: Microsoft’s willingness to address the issue publicly and issue regular updates, including transparent release notes, fosters community trust.
Potential Risks
- Opaque Rollbacks: The lack of specific detail regarding which change was reverted—and why—impairs developer insight and may slow the broader community's ability to learn from such episodes. If browser makers become too reticent in these moments, the risk of repeated or parallel errors across disparate web technologies increases.
- Third-Party Dependency Management: The reliance on external libraries like HLS.js (often outside the immediate control of browser vendors) means that even rigorous browser QA cannot catch every conflict, particularly when such libraries are embedded deep within the web’s infrastructure.
- AI Overreach: As Microsoft infuses more of Edge with Copilot and other AI features, privacy and security implications deepen. Large-scale data analysis, context scraping, and automated summarization raise questions about data storage, user consent, and control—particularly in regulated or sensitive sectors.
- Update Fatigue: With a rapid release cadence, users (especially in corporate settings) may face “update fatigue,” wherein too-frequent or unpredictable changes disrupt established workflows. Clearer transparency and optionality (e.g., staged deployments or more granular update controls) are increasingly essential.
Implications for Users and Developers
For most Edge users, the practical upshot is positive: the streaming experience has returned to normal, and the browser continues to evolve toward faster, more intuitive workflows. Video content, regardless of the underlying HLS.js implementation or AAC encoding quirks, should now play as expected on affected sites.Web developers, particularly those managing large content libraries or enterprise streaming portals, face a more nuanced challenge. While the immediate crisis is resolved, best practices—such as regularly updating third-party libraries like HLS.js and validating against all major browsers—remain critically important. Microsoft’s experience is a clear signal to monitor not only the core browser changelogs but also the project health and release cycles of dependencies like HLS.js.
IT administrators, meanwhile, should verify that fleet-wide Edge distributions receive these updates promptly, especially where media playback is part of core workflows. They should also track emerging Edge features—especially Copilot-powered enhancements—to assess potential impacts on compliance, privacy regimes, and internal support needs.
The Competitive Landscape: Edge vs. The Rest
The Edge incident is also illustrative of a broader arms race among browser vendors. As Edge, Chrome, Firefox, and others iterate rapidly, the pressure to introduce new performance, security, and AI features grows. Claims like a 40% speed increase, while potentially attention-grabbing, may encourage rival vendors to redouble optimization efforts.For Microsoft, extending the appeal of Edge to both consumers and business users is paramount. Integration with Copilot and deeper ties to Microsoft 365 ecosystems are intended to entrench Edge as the default browser for the hybrid workforce—not merely as an alternative to Chrome, but as a productivity suite in its own right.
Yet, as evidenced by the recent rollback, such ambition is accompanied by new risks: only through relentless testing, communication, and cross-ecosystem collaboration can browser innovation progress without alienating users and developers through disruptive regressions.
What’s Next for Microsoft Edge?
Looking ahead, users can expect Edge to continue evolving at a rapid pace, with greater emphasis on AI, performance, and seamless integration with corporate and cloud workflows. The Copilot Chat integration signals a vision where browsers not only display content but actively interpret, summarize, and contextualize web data—turning every search or content scan into an interactive AI experience.For all its ambitions, however, the Edge team must also reckon with the realities of an ecosystem in constant flux. Maintaining robust, user-centric performance while adopting cutting-edge features and juggling third-party dependencies is no easy task.
Ultimately, Microsoft’s readiness to acknowledge, address, and communicate around issues—while continuing to push the envelope on productivity and speed—remains the best barometer for Edge’s long-term prospects. As the browser wars enter another decade, adaptability, transparency, and user trust will be as valuable as any new feature or benchmark. And as the latest Edge update has made clear, sometimes the quickest path forward is a timely step back.
Source: Neowin Microsoft temporarily removes one Edge change to fix unexpected issues