hello dear ,
i have 3 databases in as an image from each others , with the same db versions db1, db2 , db3
db1 & db2 have a synonym of a function based on database link like that :

create or replace synonym VALIDATE_FORM_USER  for VALIDATE_FORM_USER@db_link

;
db3 has the same synonym but based on user on the same database not based on dblink like that :

create or replace synonym VALIDATE_FORM_USER for USER1.VALIDATE_FORM_USER;

and i use this function in oracle forms via PL/SQL library PLL, and i have one application server with one source files points to the three databases db1 , db2 & db3 with different configuration url app1 , app2 & app3, the forms of app1 & app2 based on db1 & db2 using the mentioned function is working normally , but when open the same form from the app3 which based on db3 i got "ORA-02019: connection description for remote database not found" , and need to compile the pll on the db3 "and if compile in db3 , apps based on db1 & db2 raise the same error".
i need to share the same the same source file to all applications with recompile the screen for each project