App crashing in Sierra - Etre and Crash report analysis anyone?

Hi. A third party audio recording app that has been pretty stable in Sierra, began crashing on me when

seeking to complete some editing yesterday. After editing an open audio document (a graphic waveform in appearance) and choosing the Save command, the file waveform window remained open and two Error dialog boxes appeared per screenshot. “Unable to Draw” and below that, Error -43 “File not found. Deleting workspace file from AFM_Kill.” Clicking Continue on the -43 was non-responsive. Clicking “Ok” - as I recall either crashed the app, or was unresponsive also and the only way to ‘exit’ the situation was to Force Quit. I ran the "EtreCheckPro app and also have a Crash Report generated by Mac at the time it

occurred. Would welcome any suggestions on what could be the issue. I did the usual fix-permissions/disk first aid routine, tried to de-clutter my desktop file a bit, and ran Onyx... I'm interested

in whether the CrashReport could identify what was going on...and why it was specific to the particular document I was working on since, subsequently some other work has not generated the errors in this app. I can say that there is a 'temp file' creation going on with each Edit in this app... that is, if I copy cut and paste .. as well as with the Save command. This all occurs in an invisible file realm...and am not sure specifically what the logistics or relevance of that might be - other than maybe some taxing of RAM occurring... or some 'addressing' thing having to do with permissions.. i seem to recall an issue in the past after a new OS install where this app was finnicky about what drive it was assigned to 'write' to and i think i had to reconfigure some permissions so it would recognize the HD. Normally the write-to is the HD Volume. The "scratch disk" setting of this app is set to utilize a portion of the HD's free space to hold audio data that's been cut or copied as well as temp files for "undo" purposes. By default the app uses the drive with the most free space.

Thanks for any thoughts! I know it's a long explanation but trying to include as much info upfront as possible.