Can't use code generators because of "object reference not set to an instance of..."

What can cause this behaviour?

I'm trying to generate code via ADO.NET EntityObject/Poco/SelfTracking Generator and i get only "object reference not set to an instance of an object" error

I can add i'm using EF4 with OracleProvider and previously i've generated code with EdmGen2, but right now i'd like to generate POCO classes from existing .edmx file which was created above existing databa开发者_JAVA百科se.

I never used this feature, but you might want to look at the stack trace / inner exception of the exception, it will help you track the exception source so it will easier for users to help.

Or even maybe it's a broken relationship or maybe some line of your patial-class constructors or other functions is throwing this error.