"error: solnum out of range" RF module, mode analysis

Hi,

I am doing a mode analysis for a plasmonic waveguide, now, when i am trying to open the file, the whole loading process of opening the model is done, then a message appears that tell me that "solnum is out of range", and the model doesn't open, and I need the results in this file. Thanks in advance.

Best Regards,
Abdalrahman