How to track PM_TOT using CMAQv5.5-ISAM

Dear teachers, I used CMAQv5.5-ISAM to analyze PM2.5 and found that PM_TOT can be directly selected in version 5.5. However, after trying the following methods, the same error persisted:1. Reducing the number of source categories being tracked;2. Modifying SA_DEFN.F by setting VOC to FALSE (as I suspected the issue might be due to too many species in VOC);3. Increasing the number of computational nodes. Is there any teacher who can help me look at my problem, which has been bothering me for a long time . Thank you very much for your answers!

This is actually a easy problem to solve. You just need to use IOAPI large version rather than the normal IOAPI version since you are trying to track a lot of sources or lots of regions tagged.
For IOAPI large, you can search it and it is easy to find here.