"(SPMHGE-268): brd2odb.exe had errors, use Viewlog to review the log file." What did I break?

I'm trying to export an ODB++ archive from a simple board design in Orcad PCB Designer Professional . However, the process seems to be broken for this specific BRD file and I'm not sure why.

Specifically, the error I get is "<company file structure>/Rev-/Board Layout/log_brd2odb.log' does not exist", followed by a "(SPMHGE-268): brd2odb.exe had errors, use Viewlog to review the log file." in the command window. The end result is that I get a bunch of .OUT files spewed into the Board Layout folder but no .TGZ archive.

However, I'm able to successfully run the ODB++ export on a second, much more complex board file and receive a tidy .TGZ archive no problems, so I suspect the problem lies somewhere in my simple board design...

Things I've tried to get a successful export:

- Replaced spaces in the file name with underscores, inspired by: https://techsupport.ema-eda.com/support/solutions/articles/48001143609-error-when-generating-odb-export - Process seemed to get further along before erroring out in the same way (more things showing up in the command window).

- Force-feeding OrCAD a log file; I created a text file named "log_brd2odb.log" and placed it in the same directory as the BRD file. This suppressed the error saying the file doesn't exist, but I still didn't get a successful export and received the SPMGHE-268 error. Furthermore, it even popped up the empty log file in the report viewer. Either way I have no idea what the actual error comes from since it's not writing it out to a log file regardless.

- Checked my environmental variables as described in https://community.cadence.com/cadence_technology_forums/pcb-design/f/pcb-design/23913/odb-export-fails-brd2odb-log-does-not-exist. My ALLEGRO_BRD2ODB variable points to a MentorGraphics folder instead of a Valor folder since that was 10+ years ago in the original post, but the rest is still the same. I also added the path %ALLEGRO_BRD2ODB%\nv\bin to my user variables. No dice here.

- Reinstalled ODB++ Inside by downloading the most recent version and running the installer. I didn't uninstall the old one, but given that I was able to export a TGZ archive from the previous complex board no issues before and after doing this, I don't think this was the issue.

- Checked that my file naming convention was similar between the complex working board and the broken simple board; both files now have underscores in their name and no spaces. I'm not using any exotic characters in either filename. Both BRD files have file paths with spaces in them, but given that the complex board works I don't think this is a factor.

About the only thing I can think to do at this point is to save the BRD file off to a safe place, blow away the Board Layout folder and start again from a fresh new folder. It'll mean losing the parameters for my drill charts and whatnot but if I can fix it doing that it's not a big deal.

Any suggestions? I'm out of ideas apart from starting over as mentioned above.

Thanks!