Licence Validation Theme X ist not possible

We bought two licences for Theme X in 2016. After restarting WordPress from a backup, the theme no longer works correctly and the licence code is missing. When I enter it for validation, nothing happens and I see a blank white page. How can I license the theme correctly again?

Hi @Firmenauskunft,

Please contact the author of your purchased theme, the theme author will assist you.

How to contact an author to get support or for any technical query: