typo3 8 git: file list missing

I updated my copy of typo3 8 to the latest git version, and many backend modules were disabled. I've enabled most of them, but the file list module is still missing.

[8:39] 
the extension manager does not let me enable nor disable it

[8:39] 
is there something I can do to get it back?

[8:41] 
I manually added it to typo3conf/PackageStates.php and then disabled and re-enable a random extension. now it's back.