Migration Oracle forms 6i to 12c .pll library error ORA-06508

Step 1: Open the form builder 

Step 2:   Click on open button 

Step 3 : Select calendar.pll file and then click on open button 

Step 4 : Open the form and attached the library 

Initially, close the form builder, open it again, open the calendar.pll as a file, compile and generate it, save it, and close the form builder. Reopen the form builder again, open your form, attach the library, then compile and generate the form, then save it and run it.