I recently ran into an error in my development environment after applying v15 HF6 files and wasn’t able to log in. The error was “Object reference not set to an instance of an object. at Astea.AO.Version.GetCustomizationServerVersion()”.
After reviewing the changes, I realized that I needed to run Sync Templates in Configuration editor followed by IISReset to add the “Version” property to the customizations setting.
I hope this helps anyone that runs into a similar error.
