In your Criteria Model Class are you using the attibute (below one)?
[EPiServerDataStore(AutomaticallyRemapStore = true)]
As, it is also mentioned in the link you shared, that the vistor group model is saved into DDS. That's why you need to allow the model remapping by setting it's value to true.
If it don't work, can you please share the code? It will be easy to identify the issue.
If you look into your log files, there are probably more information there
I found the error from the browser inspect window viewing the call in the network tab stating that the identifier, which is the namespace was too long. So it's a sql error from a data field with a 128 char limit. Our namespaces are quit long so a few of the VGs were getting this error. After shortening the name of the file they worked.
Would be nice if Epi could make those errors more apparent. Could save a lot of time for developers :)
I'm getting this error displayed in a dialog window after creating a custom visitor group. The custom visitor group's files are entirely identical to an existing custom visitor group that is working as expected. I found this forum post from 2015 with 2 answers that don't really seem to address the issue: https://world.episerver.com/forum/developer-forum/Developer-to-developer/2015/2/personalization/
Anyone able to shed light on this? Seems like a bug in epi.
Thanks in advanced.