Error when Choosing a Post Processor: “The selected post processor is invalid or license has expired.”

This article addresses the CAMWorks error “The selected post processor is invalid or license has expired” when attempting to assign a post to a machine.



The user receives the error when he or she is assigning the post processor to a machine using Edit/Define Machine > Post Processor and browsing for the .CTL file.




The incorrect post processor was selected or the folder that the .CTL file resides in does not have the complete post processor file set. Using a custom post processor file that is restricted to another organization will trigger the error as well. 



1. Make sure the correct machine is active by highlighting the machine and clicking Select. For example, if a post processor for a Turn machine was selected while a Mill machine is active, we will be seeing this error.



2. If the first solution does not resolve the issue, check the folder in which your post processor is located. Aside from the .CTL file, we will need the .LNG and .PINF files that are usually provided and downloaded in the same folder. Acceptable post files are also .LIB and .KIN. Simply find or re-download the folder again and move all the files to your post processor folder.




3. Custom-made post processors are linked to the license information used on the computer as they are designed for a specific organization. If the organizations differ between the license file and the post processor, then the error will be triggered. Replace the selected post processor file with the one intended for your company. 


If you have any additional questions, please contact Hawk Ridge Systems Technical Support at 877-266-4469 or

Was this article helpful?
0 out of 0 found this helpful



Please sign in to leave a comment.