Getting a t"test period is over" message although I got a license

I have been using Glyphs succesfully for about a year and I am very pleased with it.
Problem: All of a sudden I get a “test period is over” message when launching Glyphs. I paid for the license in 2015. I am using Yosemite 10.10.3

Any ideas on how to solve this?

Thank you!

Please reinstall the license. If you have trouble with it:

Big thanks!