I ended up working with UiPath support as well as a ML engineer on this issue and found a work-around and a fix. I am on a Windows 7 machine, which has problems with the newest IntelligentOCR packages and the OCR engines according to support.
There is an alternate OCR Engine that the ML engineer point out for me which seems to work for all the invoices that I was having problems with. UiPath.OmniPage.Activities. This package allowed the use of the OnminPage OCR Engine. I found this work-around to be enough to get me working again.
The other option was to upgrade my machine to Windows 10 since certain parts needed for the OCR engines was not supported in Windows 7 any longer. I will be upgrading to Windows 10 soon so I will see if that fixes the issues. Here is the support summary:
Issue Description:
Digitize Document activity throws an error for some PDFs.Resolution:
Please consider upgrading to Windows 10 where Microsoft OCR module is pre-installed.
Also, please contact UiPath forum for assistance until the packages are officially supported.