Cubase gets stuck while using soundtoys 5 bundle

[fese]

To verify if its really Soundtoys, you can use my tutorial here:
(Requires a bit of work, though)

How to analyse Cubase crash dumps on Windows

A couple of years ago, I encountered the dreaded “Cubase hang on project close” problem. The culprit is usually a plugin. But how to find out? In this case, start WinDbg, but Select “File->Attach to Process” and then select Cubase. Do this when you already closed the project and Cubase hangs. Now just type “k” in the command window. You then get a stack trace, which can be really long. In there, search for a plugin name that you used in the project. Most likely, this is the culprit for the hang…

(See the first post there on how to get WinDbg)

If it is really the case, a bug report with Soundtoys is the best option.