Hello Christian,
I have the same problem, as you can see here: https://www.flyalaska.ch
I wanted to deactivate the plugin, but instead this error showed up and now I can’t even get to my dashboard… I already informed my host, but I know from experience, that it can take several days until he replies. I was wondering, if you could help me, get back the website?
Thank you very much and best regards,
Tashi