Hi,
I'm using dotConnect 6.10.141
I call in ambient transaction to a SP that deffer constrained until commit.
Using: EXECUTE IMMEDIATE 'SET CONSTRAINT ALL deferred';
If trying to commit when the SP brakes one of the FK's you will get a NullReferenceException instead of any other indicative exception of the error.
NullReferenceException in Dispose of transaction scope
Are you using plain ADO.NET or Entity Framework? Does the problem persist with the 6.30.202 version of dotConnect for Oracle? Please send us a small test project with the corresponding DDL/DML script to reproduce the problem in our environment.