"Empty Zone ID" in Bemob + Propeller Campaign

I'm getting an "Empty Zone ID" with my Propeller + Bemob campaign. That particular IP seems to receive most of the traffic. I spoke with Bemob and was told I had a script on my LP. I removed the script and started a fresh campaign, but the problem persists. I tried a new traffic source and didn't see the problem. Clearly, it has to do with the Bemob + Propeller campaign. I have read threads on this topic but haven't found a direct answer. Does anyone have an idea what my problem is? @BeMob ??? @PropellerAds