We all have encountered this error while updating. There are many troubleshooting steps :
1. Type in the search box on the bottom of the screen Command Prompt, right click and select run as admin then type in it sfc /scannow and let it be completed, once done, restart your pc
2. Then type this another command dism.exe /online /cleanup-image /restorehealth and let it be completed. Once both of them are completed, restart your pc. Your issue should be fixed
3. If not fixed, you can update your pc using the Media Creation Tool and you are good to go.