When trying to execute a test in Performance Center version 11.52, at the "reserve a time slot" step the Performance Center client shows the login page URL or the message 'Client has stopped working'.
From the same project it is not possible to reserve a time slot as well.
The issue appears for a project which was upgraded from version 11.x.
Please follow the steps below to workaround the issue:
Copy the affected project from within Site Administration -> Site Projects -> Create Project and select option 3 – Create a project from copying from another project.
NOTE: The project needs to be deactivated while it is being copied.
That will allow creating a new project which can properly communicate with the Lab Management project. The communication is needed for the timeslot creation.