Thanks all for the feedback and I'm glad David's suggestion of deleting the Deployment Manager Add-in seems to be working for you.
Our developers are still trying to reproduce this issue, but we haven't had any luck so far, I'm afraid.
To help us, it would be really helpful if anyone who has this issue could let us know the following, please:
- Which versions of SSMS you have installed
- Which version of SSMS you are using
- The OS version
- Any other plug-ins you have installed in SSMS