I didn't see this one on the list of 'known issues'. To recreate the minimal case to see the issue:
1. Create a new .uir file.
2. Add an ActiveX control (I used Microsoft Web Browser).
3. Attempt to convert to text by selection Options -> Save in text format...
4. Complete the save dialogue.
5. CVI crashes with the message "Labwindows/CVI has stopped working. A problem caused the program to stop working correctly. Please close the program."
The crash also occurs on save when the 'auto-save to .tui' option is turned on.
The issue doesn't seem to be present in CVI 2015. I haven't tried any other versions.
This issue appears to occur on both Win7 and Win10.