There are a few known issues that may cause FontLab to crash unexpectedly

1. When you click Cmd-S (Ctrl-S) and then quit FontLab immediately, FontLab may crash because it quits during the file save operation. 

We are working on the solution.

2. Unexpected crashes happen sometimes when you delete a node, copy-paste a contour, switch layers etc. In this case please send us the crash reports (both the system one and the one produced by FontLab on the next start) with the description of what you did before the crash.