Issues in opening customized work item from team system web access in team foundation server

There was another long running interesting issue of one of my customers which I was able to fix today, where we were not able to open customized work items from team system web access and were getting the following error message:

Exception Message: Error during serialization or deserialization using the JSON JavaScriptSerializer. The length of the string exceeds the value set on the maxJsonLength property.

Server: TFS 2012 Update 3

Solution:

We found that customer had a very complicated work item types and JSON size of work item types exceeded the default value which is 20MB.

Hence, we advised them to increase JSON limit to something like 40MB using the following appSettings entry in web.config.

<add key="maxJsonLength" value="41943040" /> and that resolved the issue.

Written by: Nitish Nagpal, Support Escalation Engineer

Reviewed by: Serkan Inci, Product Group