The global.asax loads the SkinConfigManager in the Application_BeginRequest, which looks up the current page skin by getting the entire Page object. The Page object has some properties which didn't exist prior to 2.3.9.7.
We could update the PageSettings.cs to check for dbnull on all of these properties or we could wrap the SkinConfigManager load in global.asax in a try/catch.
A workaround is to upgrade to any version between 2.3.9.7 and 2.9.0.1 and then upgrade to 2.9.0.1.
The global.asax loads the SkinConfigManager in the Application_BeginRequest, which looks up the current page skin by getting the entire Page object. The Page object has some properties which didn't exist prior to 2.3.9.7.
We could update the PageSettings.cs to check for dbnull on all of these properties or we could wrap the SkinConfigManager load in global.asax in a try/catch.
A workaround is to upgrade to any version between 2.3.9.7 and 2.9.0.1 and then upgrade to 2.9.0.1.