CorelDraw X8 fails after Substitute Missing Fonts dialog box

Running Corel X8 v18.1.0.661 on Win10x64.

When launching or loading a CDR that requires a font substitution to a later version of the font, Corel exits (crashes, I'm guessing) with no apparent message or output. The crash happens after clicking [OK] on the "Substitute Missing Fonts" dialog box. It fails whether [X] Permanent or [X] Temporary is chosen.

I have reset the Corel Font Manager database with the [F8] on launch protocol, and results have not changed.

I cannot re-install Corel without the Font Manager, because my installation is crippled (this is a *long* standing issue that support has been unable to resolve. I can only install with default options - I can't even see what I'm doing during the install because of some bizarre interaction between the X8 installer and my system ... however, I have been using Corel successfully for years).

I am running a lot of fonts - over 1200 (I am a font developer). However, I have a *large* system (10-core i9-9900X, 128GB physical memory, large SSD drives). No other program of the *many* applications I run has any problem dealing with the number / size of fonts.

I cannot pare down my fonts directory, because many other apps I run depend on them.

Loading on a fresh Win10 system might be a choice, but I am concerned with failing authentication because of "too many installs".

Does anyone *please* have some concrete suggestions. I am dead in the water and cannot access my CDR file contents!!

-Clint Goss