After running the upgrade process from 6.3.500 to 8.2.5905 I tried to visit the homepage but saw the following error:
Database mapped field uses different type 'System.Nullable`1[[System.Decimal, mscorlib, Version=18.104.22.168, Culture=neutral, PublicKeyToken=b77a5c561934e089]]'.
Parameter name: methodCallExpression
Actual value was re-t.FieldValue("Sequence").
Changing the related widget code from GetValue<decimal> to GetValue<decimal?> resolved it, but I'm curious why this might have happened.
Secondly, when we tried to log into the backend, I got the exception:
I unfortunately didn't capture the full error message, as I somehow resolved it by disabling BrowserLink, by adding the following config to web.config appsettings:
<add key="vs:EnableBrowserLink" value="false" />
after that everything seems to be fine, and removing that key does not bring the error back.
I'm not sure what happened, but logging it here in case it might be helpful to anyone else