I can tell you that the plugin requests a "
maxwell_solidworks" license, and will refuse to export .mxs files if this cannot be checked out (an additional "
maxwell_bundle" license type is also checked/accepted). If this fails, you will find information about the failure printed in the log viewer (Tools > Maxwell > Log Viewer) after the License Activator closes.
My guess would be that you will find a "No license for product" message in the error report, possibly indicating that you have a Studio license installed (since Studio is working), but not a plugin one. However, I am not an authority on licensing, so if this does not help get you going, please copy the error report from the Log Viewer, and contact support (via
https://portal.nextlimit.com) with it, to see what they say.