How to fix a workspace in Eclipse that does not open anymore (because of EGit)?

My Eclipse workspace doesn't open anymore. Eclipse started to launch , then..nothing.
Here is my log :

!ENTRY org.eclipse.egit.ui 2 0 2020-10-26 22:14:42.055
!MESSAGE Warning: The environment variable HOME is not set. The following directory will be used to store the Git
user global configuration and to define the default location to store repositories: 'C:\Users\xav_m'. If this is
not correct please set the HOME environment variable and restart Eclipse. Otherwise Git for Windows and
EGit might behave differently since they see different configuration options.
This warning can be switched off on the Team > Git > Confirmations and Warnings preference page.
!ENTRY org.eclipse.ui.workbench 4 0 2020-10-26 18:34:52.194
!MESSAGE FrameworkEvent ERROR
!STACK 0
java.lang.NullPointerException
	at org.eclipse.ui.internal.AbstractWorkingSetManager.getUniqueDescriptors(AbstractWorkingSetManager.java:685)
	at org.eclipse.ui.internal.AbstractWorkingSetManager.bundleChanged(AbstractWorkingSetManager.java:632)
	at org.eclipse.osgi.internal.framework.BundleContextImpl.dispatchEvent(BundleContextImpl.java:973)
	at org.eclipse.osgi.framework.eventmgr.EventManager.dispatchEvent(EventManager.java:234)
	at org.eclipse.osgi.framework.eventmgr.EventManager$EventThread.run(EventManager.java:345)

I installed GitBash few weeks ago but never used it before, except to config my user name and email address used on my GitHub account. I haven't created a local repository yet.
I installed Egit plugin few weeks ago, without used it, and updated it today. Since this update, when I try to launch Eclispe,I have the message above.

I tried to change the variable Home with value "%USERPROFILE%" , just to see, but I had the following message:

!ENTRY org.eclipse.ui.workbench 4 0 2020-10-26 18:29:50.338
!MESSAGE FrameworkEvent ERROR
!STACK 0
java.lang.NullPointerException
	at org.eclipse.ui.internal.AbstractWorkingSetManager.getUniqueDescriptors(AbstractWorkingSetManager.java:685)
	at org.eclipse.ui.internal.AbstractWorkingSetManager.bundleChanged(AbstractWorkingSetManager.java:632)
	at org.eclipse.osgi.internal.framework.BundleContextImpl.dispatchEvent(BundleContextImpl.java:973)
	at org.eclipse.osgi.framework.eventmgr.EventManager.dispatchEvent(EventManager.java:234)
	at org.eclipse.osgi.framework.eventmgr.EventManager$EventThread.run(EventManager.java:345)

Means the same message, without the message about git.
I created a local repository "git" and init it in my folder user, it didn't work.
Should I desinstall GitBash? Or remove the .metadata in my worskpace?
Thank you for your help

Ok, after few research, I tried the following and it worked for me:
Go to .metadata/.plugins/org.eclipse.e4.workbench/workbench.xmi and remove workbench.xmi

And Eclipse works now, but of course I don't why.
If someone has a little clue, I take it

Don't attempt to recover the workspace. Create a new workspace. If all of your projects are stored in a remote git repository, just reimport the projects from your local repository (although it's not clear whether you've ever cloned a repository). If any of the projects are not stored in git, but in local directories on the local disk, then just reimport from those locations (even if that location is within the original workspace).