@gmp - do you have "Rescan All Plugins" and "Scan in Sandbox" checked with "Scan on Startup" selected?
 
This might be a dangerous combination, especially if your project is trying to load a VST currently being scanned in the sandbox.
 
Personally, I almost never have "Rescan All Plugins" checked, and I now have "Manual Scan" selected. I do a manual scan any time I install a new plugin.

Scanning has nothing to do with it and its not possible for a plugin to be scanned while its loaded. 
 
Gerry your crash happens during transient detection which is when waveforms are being created. I'ts completely unrelated to anything new in recent versions. Is it possible you have some data corruption in your picture cache? Try clearing your picture cache and reloading that project. If it recurs let me know.

Noel, steps for clearing picture cache?
 

Using Windows Explorer open the path shown in Preferences > File > Audio Data "Picture Folder."
 
Delete all the files in the folder.

Thanks, scook. I have a couple of projects that play, but visuals behave oddly. (virtual meters don't move). I'll bet something like thiis could be the culprit.
 

FWIW I just added defensive code to prevent this specific rare crash from happening again.

Noel Borthwick [Cakewalk]
FWIW I just added defensive code to prevent this specific rare crash from happening again.

Super news!  After that crash requiring a reboot I decided to go back to 2018.07, but now I'll go back to using 2018.09 and see if it happens again. Since 2013 I've had a macro that deletes the complete pic cache at 11 pm, so any corruption there was deleted. Thanks for figuring the cause of this. I'm looking forward to having the defensive code in the next release.

Further investigation:
Deleting the picture cache did not fix the crash (I know this wasn't meant for me but I gave it a shot anyway).
 
Cakewalk still crashes if project opens while toast notifications are running - BUT - if I let the notifications completely finish, and then click to open the project, there is no crash. 

jgarland
Further investigation:
Deleting the picture cache did not fix the crash (I know this wasn't meant for me but I gave it a shot anyway).
 
Cakewalk still crashes if project opens while toast notifications are running - BUT - if I let the notifications completely finish, and then click to open the project, there is no crash. 

It seems like what you're saying is that you're double clicking on a CWP while the toast notifications are running. I assume when you open CbB it's loading a template or a song by default and while that is loading you're double clicking on a different CWP because that's the one you want to work on.
 
What I do is while CbB is closed, I double click on the song I want to work on and then it opens CbB. Hope this helps

jgarland
Further investigation:
Deleting the picture cache did not fix the crash (I know this wasn't meant for me but I gave it a shot anyway).
 
Cakewalk still crashes if project opens while toast notifications are running - BUT - if I let the notifications completely finish, and then click to open the project, there is no crash. 

Hmm I looked at your dump and while I see a crash while processing Rematrix Solo, the crash doesn't appear to be related to Toast notifications. Can you share the cwp file just in case we can repro it using that?