Use adadmin => Generate Applications Files menu => Generate form files
And regenerate for all forms.
AD utilities can support a maximum of 999 workers. Your
current database configuration supports a maximum of 56 workers.
Oracle recommends that you use between 3 and 12 workers.
Enter the number of workers  :
Your current character set is "AL32UTF8".
Do you want to generate Oracle Forms objects
using this character set [Yes] ?
Do you want to regenerate Oracle Forms PL/SQL library files [Yes] ?
Do you want to regenerate Oracle Forms menu files [Yes] ?
Do you want to regenerate Oracle Forms executable files [Yes] ?
Enter list of products ('all' for all products) [all] :
Do I need to relink executables?
Sorry, I was driving.
If you only intend to recompile the invalid forms, then you don’t need to run other optional.
You may choose to relink ad executables when you run into form server issues, FRM-92101 for example, which is different from individual form issues, like you are having now.