This Error Starts Appear After Migration from 9i to 10gR2 , and using forms/reports 6i I read lot about this error but nothing been useful for me , I Found Some Document On metalink talk about this error , you check this error on metalink under BUG Database , the Bug Number is 309292121.
QUERY BUILDER is not showing the table relation between master and detailed
tables when conneted to 8.1.7 OR 126.96.36.199 database. With 188.8.131.52 data base
there is no problem.
Testcase step-by-step instructions:
1) In the report builder, open the query builder.
3) Select the table EMP from the list and press the include button.
4) Select the table DEPT from the list and press the include button.
After I follow the above steps and rebuild the constraint the same error appear.
So i post this article maybe it will be useful.
After did some research i found that the error appears Because 10gR2 its not certified with forms/reports 6i.
so you could try the below solution :
1-Install Oracle 10gR1.
2-Upgrade forms/reports 6i to 10g.