Hello,
Yes, that’s it.
There are the following errors related to server settings that you need to fix:
1) ModSecurity: Output filter: Response body too large (over limit of 1048576, total not specified)
2) PHP Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 28672 bytes)
So, contact your hosting provider and ask them to fix errors. After that clear the server error logs and try to open Theme Options again. Let me know if you still have problems after that and what errors in the error log appear after that.
Regards