Exception while executing request: First query term may not have NQ or OR prefix

[CliffB]

I can't publish or test a topic block because of this server error: "Exception while executing request: First query term may not have NQ or OR prefix".

What does that mean?

[Mark Manders]

What is the query you are using? 

[CliffB · Accepted solution]

It was just Conditions in a pair of decision branches. Not to worry, deleting the decision and recreating it has fixed the problem. Just some bug I guess.