I started facing this error after I removed 2 projects from the “Local Drive C”
Here’s how it worked for me
Uninstalled Unity hub
Installed the beta Unity Hub from this link
Unity Hub v2.0 beta is now available for download - Unity Forum
Opened Unity Hub Beta [Checked in the project list, if those removed projects were still in the list. They were not anymore]
Installed Unity Hub latest official one
Uninstalled Unity Hub Beta
Worked!
Hope this helps others!