Hello Larry Miclette,
Can you tell me what steps you followed when upgrading from 4.1?
If you are using Sitefinity 4.1 and want to upgrade to 4.3, the correct procedure will be:
4.1 1339 -> 4.1 SP3 1574 - then make sure the site is running, the modules are initialized.
4.1 SP3 1574 - 4.2 / 4.2 SP1 - verify that everything works.
4.2/4.2 SP1 - 4.3.
This process is highly recommended
due to the fact that there were a lot of changes during the different versions of Sitefinity. Skipping any of the steps or directly upgrading may result in corrupted project.
The problem is most likely to be coming from some corrupted data in the project, as a result of the direct upgrade. Can you tell us if you have access to the backend?
the Telerik team
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