I purchased the Student Edition for my master's research but it's not sufficient. Can I upgrade it to analyze larger models or what should I do?
You should read over the detailed information that each of the versions offers. Based on that information you can establish whether you need to upgrade or use the current version installed.
There are three versions of this product but I believe those two other versions need to be paid before using. You can check for these versions on the homepage of the developer.