Hi Neil,
Thank you for reporting to us this case.
Our team is working on eliminating of crash issues.
I want to ask you, please try to reproduce this and send us the failure file. You can find it by the following way: %temp% and select the 'MSBuild_SOMEGUID.failure' file with the appropriate time when the crash happened.
The additional help for us to understand the reason of this crash would be your Bug Report from IDE: Help -> Report a Bug.
We appreciate your feedback. It helps us to make The Welkin Suite better.
Thank you,
Kate