Qt Creator hangs, when a project in a session cannot be loaded

I have a session with 8 projects.
One is located on a network-path.
If the path isn't mounted and I open the session I get an error-message:
"Failed opening project '/home/marcel/server/home/dev/project_test/project_test.pro': Project file doesn't exist".
If I click "Ok" Qt Creator doesn't respond anymore and has a cpu utilization of 100%.

How to reproduce:
Create two projects and add them to a session.
Let's name them "app" and "libs".
Add "libs" as a dependency to "app".
Rename or move the directory "app".
Open Qt Creator and load session -> error message (see above) -> Qt Creator hangs
If you rename or move both it also hangs.
If you only rename the directory "libs" you get the error message and after that the prompt, if you want to keep or remove the projects from the session.

Seems to be a problem with the dependencies.