I am having a similar problem trying to open a new AE Template. When trying to open the project I get a message I cannot bypass: "It seems you have a collapsible layer". It will be un-collapsed"... But no matter how many times I press the OK button it does nothing. I have to force quit to get out. I also tried importing the project into new project but same result.
I am using CC 2021 v 18.4.1 on a Mac Mini M1 OS 11.6.