This issue UI freeze in Content Manager is not new, I did notice it already after the last UK upgrade 1.13.16.0
But here with those 30 livery packages to upgrade, it is really painful
There’s a thread with a vote button here
Could please add your vote if you are impacted:
Content Manager Freezes - Bugs & Issues / Miscellaneous - Microsoft Flight Simulator Forums
And I open a Zendesk ticket, as it is 100% reproducible on my end