Wowza Community

Zero sized function / Data format incorrect / packetSizeReset


A few hours ago Wowza encountered an issue that caused it to stop responding, and then later resume with the following errors:

ERROR server comment 2009-03-26 12:35:45 - - - - - 409980.624 - - - - - - - Data format in

correct, killing client connection.

ERROR server comment 2009-03-26 12:35:45 - - - - - 409980.624 - - - - - - - Zero sized fun

ction (client): type:20 size:0 index:1536

ERROR server comment 2009-03-26 12:35:45 - - - - - 409980.624 - - - - - - - packetSizeRese

t: 8:128

We recently added some additional RAM to the server that this occurred on - could this be a result of faulty RAM? We don’t really want to take the server down to do a memtest unless we really have to though.

Thanks in advance for any help!

It could be. I am not sure. This usually means a single connection is out of sync for some reason or other. It certainly could happen due to bad memory.


Be sure you are running latest version of Wowza. There was a small change to fix a problem that could lead to this error message. If you are still seeing this error after upgrade to latest version then be sure server is tuned properly. It could be caused by long garbage collection pauses. If you are still seeing the problem, then it is most likely an errant RTMP connection.


I think updating did help. You can update to 2.2.3 here:

Then you can update to here:


We are seeing this in Wowza 3, any further ideas? We feel we have made all the garbage collection tuning etc… They are virtual machines and we are adding memory soon as well. Any other ideas would be great.

Was there a resolution that anyone found to this problem? We’re seeing it in our error logs, and we’re trying to understand if it’s a hardware problem or if we should focus elsewhere in our stack.


Thanks Charlie! We’re upgrading now, and I’ll report back with the results.

Hi monvural/Charlie, we are facing the same error with Wowza 2.1.2.

Our windows Flash clients do not have any issue, but ‘clients killed’ with Mac.

Can you tell us if your problem is resolved now?

Thanks much rrlanham, we have not been able to replicate this issue with the latest stable build 2.2.3, so the PktSizeReset issue appears resolved.