Thank you for contacting us with the issue you are faced with.
May I please ask you to provide us with the additional information so that we could find the reason for this:
1. Is the issue reproduced for one of the projects in your solution or for both of them?
2. Is this reproduced when you build changes related to some metadata type files, for example, for classes only, or for different files?
3. Can you please tell us (or make a screen) what do you see in TWS Output panel when you are getting the message that IDE is going to be restarted? (This can be the same screen as you have sent but including the view of the Output panel)
Also, I kindly ask you to send us a bug report directly from the IDE using the menu Help -> Report a Bug. Please enable the 'Attach Log File' checkbox - this way we will receive your TWS logs which would help us in our investigation. In addition, you can add your email in the appropriate field so that we know that this bug report is from you.