Here's the error I just got using the web console report function on the latest Firefox Version 59.0.2 (64bit) on my Mac:
WebGL Memory - Total: 256MB, Used: 243MB, Free: 12MB (Filename: ./Runtime/Export/Debug.bindings.h Line: 43) f8dd84cc-a73d-da4f-9ef0-c705d95d7f5f:8776:6
Cannot enlarge memory arrays. Either (1) compile with -s TOTAL_MEMORY=X with X higher than the current value 268435456, (2) compile with -s ALLOW_MEMORY_GROWTH=1 which adjusts the size at runtime but prevents some optimizations, (3) set Module.TOTAL_MEMORY to a higher value before the program runs, or if you want malloc to return NULL (0) instead of this abort, compile with -s ABORTING_MALLOC=0
Is this the same that you're getting? I get this all the time as well. It reports as an uncaught execption which causes the crash. Hopefully this information will help in addressing the issue, programatically.
Just trying to help,
Lester