@Barb. Sorry to hear the Download Manager crash is still there. I thought that some of the subtle bug fixes that dmik did fixed it. I notice you're using SNAP, does the crash happen in safe mode or with MOZ_ACCELERATED=0 set?
You do know about the workaround of not using the DownLoad Manager? Preferences-->Browser-->Downloads and click use a progress bar.
@Greggory, no I don't have a version of Enigmail that works with newer TB or SM. The problem is that Enigmail now uses CTYPES to load functions from native DLLs and I'm probably not skillful enough to write the JavaScript to open libc066.dll and use the libc functions to open and run PGP.
One thing I was curious about is how the fonts look for everyone?