Troy - thanks for your post. However, this community is for overall feedback on our community site. What Mentor product are you using -- PADS? Let me know and I will move your post to the appropriate product community. thanks!
UPDATE: Am moving this post to this community, which seems a more appropriate location for our members to help out Troy. Let me know if this isn't the best area.
It is impossible to tell you why it happened without seeing the file. It could be a padstack issue, a settings issue or a CAM setup issue. Please submit a Service Request, attach the .pcb file used to make the boards and tell us exactly where the missing antipads are.
Never use CAM planes. It's a legacy option, and there are many things that can't be checked on them, split planes being on of the major ones. Always use routing/split in CAM documents, and make it a positive plane. You should never get an error like that again.
Thank you for your help. I'm using PADS 9.3. After trying many ways to fix the issue, we noticed a check box in the CAM Setup for pins with associated copper. The error did occur on a pad which has associated copper. After checking this box the gerbers generated correctly. We have never used the negative planes before, but we inherited a layout from another company and wanted to maintain the current layout where possible since it was already in production.
I appreciate the responses from the Mentor Graphics Communities