# MWServer crash with python server bridge **URL:** \ **Category:** Support\ **Created:** [September 25, 2012, 1:32pm UTC](https://mworks.discourse.group/t/mwserver-crash-with-python-server-bridge/643 "2012-09-25T13:32:33Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![cstawarz](https://yyz1.discourse-cdn.com/flex031/user_avatar/mworks.discourse.group/cstawarz/32/3_2.png) [@cstawarz](https://mworks.discourse.group/u/cstawarz)\ **Post date:** [September 25, 2012, 1:32pm UTC](https://mworks.discourse.group/t/mwserver-crash-with-python-server-bridge/643/1 "2012-09-25T13:32:33Z")
Hi Chris, The attached XML causes MWServer to crash when the Python server bridge is running, but not when the client bridge is running. I’m also attaching the stack trace. I can work on a reduced version of my Python script to send to you but mainly what it does is register a callback for every code. I think it has something to do with the drifting\_grating stimulus. Thank you, Mark ---
**Author:** ![cstawarz](https://yyz1.discourse-cdn.com/flex031/user_avatar/mworks.discourse.group/cstawarz/32/3_2.png) [@cstawarz](https://mworks.discourse.group/u/cstawarz)\ **Post date:** [September 25, 2012, 1:32pm UTC](https://mworks.discourse.group/t/mwserver-crash-with-python-server-bridge/643/2 "2012-09-25T13:32:33Z")
Attachments: - [TestServerBridgeCrash.xml](https://mworks.discourse.group/uploads/short-url/9LBRVamuJHVBzDCDghkB7yitfJ4.xml) (4.75 KB) - [crash.txt](https://mworks.discourse.group/uploads/short-url/h8JMigl8lJcTdDzXS2Fz5WFKEu3.txt) (68.8 KB) ---
**Author:** ![cstawarz](https://yyz1.discourse-cdn.com/flex031/user_avatar/mworks.discourse.group/cstawarz/32/3_2.png) [@cstawarz](https://mworks.discourse.group/u/cstawarz)\ **Post date:** [September 25, 2012, 7:10pm UTC](https://mworks.discourse.group/t/mwserver-crash-with-python-server-bridge/643/3 "2012-09-25T19:10:26Z")
Hi Mark, Thanks for the report. I’m able to reproduce the crash, but I haven’t yet puzzled out why it’s happening. I’ll update you when I have more info. Thanks, Chris ---
**Author:** ![cstawarz](https://yyz1.discourse-cdn.com/flex031/user_avatar/mworks.discourse.group/cstawarz/32/3_2.png) [@cstawarz](https://mworks.discourse.group/u/cstawarz)\ **Post date:** [September 28, 2012, 3:09pm UTC](https://mworks.discourse.group/t/mwserver-crash-with-python-server-bridge/643/4 "2012-09-28T15:09:17Z")
Hi Mark, I found the cause of the crash. There was a bug in the serialization of events whose values are or contain dictionaries (such as `#stimDisplayUpdate` and `#announceStimulus`, which is probably why it seemed like the drifting grating was involved). The fix will be in tonight’s nightly. Cheers, Chris ---
**Author:** ![cstawarz](https://yyz1.discourse-cdn.com/flex031/user_avatar/mworks.discourse.group/cstawarz/32/3_2.png) [@cstawarz](https://mworks.discourse.group/u/cstawarz)\ **Post date:** [September 28, 2012, 3:35pm UTC](https://mworks.discourse.group/t/mwserver-crash-with-python-server-bridge/643/5 "2012-09-28T15:35:40Z")
Great- thanks! I’ll be able to test this over the next few weeks. Best Mark ---
**Author:** ![cstawarz](https://yyz1.discourse-cdn.com/flex031/user_avatar/mworks.discourse.group/cstawarz/32/3_2.png) [@cstawarz](https://mworks.discourse.group/u/cstawarz)\ **Post date:** [September 29, 2012, 8:29pm UTC](https://mworks.discourse.group/t/mwserver-crash-with-python-server-bridge/643/6 "2012-09-29T20:29:57Z")
Just installed the latest nightly and the crash is gone. Thanks! Mark ---
**Author:** ![cstawarz](https://yyz1.discourse-cdn.com/flex031/user_avatar/mworks.discourse.group/cstawarz/32/3_2.png) [@cstawarz](https://mworks.discourse.group/u/cstawarz)\ **Post date:** [July 19, 2022, 11:40pm UTC](https://mworks.discourse.group/t/mwserver-crash-with-python-server-bridge/643/7 "2022-07-19T23:40:22Z")