Hi Darren Williams I haven't come across this issue.  Unfortunately my test system is Windows Server 2022, I did my best to install the same update and FR is still running fine.  Normally when this problem has occurred in the past I solved it by running a quick/online office repair.  Did you run the same repair option as per below?  What version of Sage 300 are you running and with what Product Update?  You can find this under Help -> Sage Support -> Support Utilities -> System Information:
(BTW I'm running Excel 365, 64-bit)

Best of luck!

They are on version 2021 PU8. Yes, the Office repair is my first option every time. They use Office 32bit. Did not work. I can confirm that when the MS Update was uninstalled FR worked, when the update was re-installed, FR failed. 

Ok so the quick repair didn't work:

Could you post the version information of office installed i.e.:

Then could you please locate the error in the Event Viewer?  If you go ahead and re-launch Statement Designer so it fails, then open Event Viewer there is going to be a specific reason for the cause of the failure:

Also, the best idea for actually attempting a fix right now vs research is to:

1. Uninstall Workstation Setup off the RDS/Workstations.
2. Open Programs and Features on the RDS/Workstations and type C++ into the Search Bar and remove ALL Redistributables:
   
3. Re-install the Windows Update.
4. Re-install Workstation Setup.
5. See if its Fixed.

Also, although its not a currently supported version, 2021 is still a recent version so have you tried opening a support case with Sage officially? 

This is a full program install on two RDS servers, both with the same issue. I do have a case open with Sage, they tried to replicate the issue and weren't able to. I really don't want to have to go to the trouble of uninstalling and reinstalling two full installs if I can avoid it.

I'll see if I can track down the Office version and the Event Viewer log when I get a chance.