Hi Adele, The program PS_ENSCRIPT is not a .pro shipped in the IDL package. Therefore, it is a user's program that you are trying to compile as part of a bigger application?. If that's the case, does IDL know where is located?. Can you find that PS_ENSCRIPT.pro somewhere in your system?. If it's there, then you need to be sure that IDL path knows where that file is. It depends how you are working, but you could find that program and copy it into the directory where your other IDL codes are located when you do the resolve_all. Also, you can set your IDL path from the IDL menu in the IDL Workbench. Simply, go to Window --> Preferences --> click in the (+) sign next to IDL and click in Paths. You can add paths there. Cheers, Fernando