Problems at loading the add-in

One of my clients has installed a newer version of SolidWorks. My plugin is also installed on that machine. When the user starts SolidWorks a small progress appear saying "Preparing SolidWorks for first use". The progress never stops, if I click cancel an error occurs and SolidWorks crashes. If I open SolidWorks again same story.

If I uninstall my plugin, SolidWorks starts normally, no more preparing for first installation. Tried installing again my plugin, and when I start SolidWorks the same "Preparing SolidWorks for first use" windows appears and I can not get around it.

Any ideas?

SolidworksApi macros