Hi, Doeke
I have dicoverd the same problem. I used the Plugin for two week and all was Great (PS. real good Plugin!) but since today I get the same message as dthekkinkad01!
and i have no idea how I can solve the Problem. Looking forward for your help.
My Versions:
GF = 2.3.6
PHP Version is = 7.2.10
and WP = 4.9.8
