As you mention several third party products, I'd recommend this test:
1. On a machine where GP is installed, have all users log out of that GP instance.
2. Rename the GP directory from something like C:\Program Files (x86)\Microsoft Dynamics\GP\ to C:\Program Files (x86)\Microsoft Dynamics\GP_OLD\
3. In Control Panel > Programs and Features, right-click on this instance of Dynamics GP and click 'Change'. In the options window that appears, choose 'Repair'. Verify the repair process goes through successfully.
The Repair process will completely re-create the entire GP directory under the original name/path, to include all folders and files, but no third party products, customizations, modified forms and reports, VBA, etc.
4. Launch Dynamics GP from this 'new' directory and see if you still re-create these script errors when changing companies.
If not, then we'd want to start testing by adding the forms and reports dictionary files and testing with those.
Next, add back the third party products, one by one, testing after each one, until the script errors appear again, at that point you'd have a pretty good idea of what is causing the script errors to occur.
I can say that so far we haven't seen any issues such as this, with users switching companies in Dynamics GP after the year end update or any other update, or really any script error issues such as this at all, to the point where it would suggest an issue with the updates.
Thank you
