I get the same error message from Scapple, which was last discussed extensively in the Scrivener forum.
Please make sure you have the latest version of Scapple, which is 1.2.4, released September 17.
Also, make sure you have the latest version of .NET on your computer.
Katherine
That was it. Thank you very much.
I have Scapple 1.2.4.0. I had stopped getting the activation error message - until yesterday. It has started again. Seems to only happen on the first use of Scapple after boot (or coming out of sleep mode). Not a serious problem. I can click through it and use Scapple just fine.
Have been using Scapple several times over the last week.
Today I started Scapple and getting the activation error message again.
FYI
Version 1.2.5.0 13th October 2019
Happened again today.