InDesign CC 2019 - 14.0.1 hang up on save

While saving a large file (256 pages). The file hangs and I get the endless spinning color wheel.

Each page had a complicated PDF on it.

I force quit InDesign and I rebuilt the prefs file.

Same problem hung up on save.

Restarted my Mac and rebuilt the prefs file again.

This time I tried saving a blank page.

Same problem.

Quite InDesign and opened the library/Preferences folder(s) and deleted the the plist files for InDesign.

Tried again and still hangs on saving just a single page blank file.

Tried all the above after launching InDesign CC 2018 (13.1)

I'm at a loss here.

Does anybody have an idea what to do?

We move the tonnage here at work and I need this machine to work with no errors.

Here are my Machine Specs:

Mac Pro (Mid 2010)

Model Name:    Mac Pro

  Model Identifier:    MacPro5,1

  Processor Name:    Quad-Core Intel Xeon

  Processor Speed:    2.4 GHz

  Number of Processors:    2

  Total Number of Cores:    8

  L2 Cache (per Core):    256 KB

  L3 Cache (per Processor):    12 MB

  Memory:    20 GB

  Boot ROM Version:    140.0.0.0.0

  SMC Version (system):    1.39f11

  SMC Version (processor tray):    1.39f11

Thanks in advance-

-Cash