Choosing Window in Menu causes Panorama X to crash

After running part of a procedure (terminated with a stop statement), I have a number of windows open. Choosing Menu->Window causes Panorama X to crash. My recollection is that I have had this happen before. Anybody else?

I’ll try to track it down.

This extract from the crash message may or may not be relevant (I know not how to interpret these things):

Crashed Thread: 0 Dispatch queue: com.apple.main-thread

Exception Type: EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: KERN_INVALID_ADDRESS at 0x00005ae270a5bec0
Exception Note: EXC_CORPSE_NOTIFY