''Bonk'' error after clicking on ''New discussion''

Metasux

Hi there,

If members click on the ''New discussion'' button at my forum (http://habtastic.nl/), they get a ''Bonk'' error:

If I post a new discussion, I don't get any error... How can I fix this error?

Greets.

hgtonight

Welcome to the community!

1. create a test account and assign it your member roles
2. log in with your test account in a different browser (or incognito tab)
3. click on new discussion
4. give us the actual error report