Crystal DLLs in GAC not found by VS 2017 while debugging

We have 4 developers on our team. Myself and one other are not experiencing this problem, but the other two are. We are operating on the same code base from the same code repository and are all running VS 2017 Professional.

When I run the project in Debug and try to generate a report, everything runs smoothly.

When my coworkers tried to do the exact same process, they would get errors that a dependent Crystal DLL could not be loaded. I confirmed that the version being looked for was in the GAC on their development boxes.

To try to work around the issue, I added the DLL to the project and added a reference to it. I also had to set "Embed Interop Types" to False so I could set "Copy Local" to True. That resolved that particular issue, but another error would appear for a different dependent Crystal DLL. I worked through a series of these "missing" DLLs (5 or 6), adding each to the project and trying again.

The last error that I got was this:

Unable to cast COM object of type 'CrystalDecisions.ReportAppServer.Controllers.ReportSourceClass' to interface type 'CrystalDecisions.ReportAppServer.Controllers.ISCRReportSource'. The operation failed because the QueryInterface call on the COM component for the interface with IID '{GUID value}' failed due to the following error: No such interface supported (Exception from HRESULT: 0x80004002 (E_NOINTERFACE)).

To reiterate, this error only occurs when debugging on two of our 4 dev boxes.

I also verified that the two boxes in question have the same Crystal installs as on my box. Those are SAP Crystal Reports 2013 SP11 AND SAP Crystal Reports runtime engine for .NET Framework (both 32-but and 64-bit).

It baffles me that the GAC DLLs are not found on two boxes but are on the other two. Any ideas?