Steps to reproduce:

• if it matters: I have set the default build directory (accidently) to:

../build-%{Asciify:%{Kit:FileSystemName}-%{BuildConfig:Name}} 

• open/create a cmake based project
• after configuring noticed the missing project name - so, modified the build directory to have some additional "bla-" after "build-"
• then I triggered a menu (Edit), immediately a message box popped up stating the build dir has changed and asked whether to use this and start a new build config - confirmed with Ok

Result: QC crashed