JSON requests

Discussion created by knisleyj on Oct 12, 2010
Latest reply on Oct 22, 2010 by rlwatson
I have a web application that makes a series of JSON requests against services and their associated layers in the process of building a dynamic legend.  Prior to ArcGIS Server 10, everything worked fine.  However, with services hosted through ArcGIS Server 10, often the JSON request returns:
{"error":{"code":500,"message":"An unexpected error occurred processing the request.","details":[]}}

The odd part is that the service can work fine for awhile, and then at a seemingly random point in time it will stop returning the expected JSON results and instead return the error above.  Manually clearing the cache (through //server/arcgis/rest/admin) works for awhile, but eventually the error will occur again, making my current legend implementation very unreliable.

A few strange things typically occur as well:
1)  The entire service, in my experience, has never been affected as a whole.  Normally it's only a single feature layer under the service that generates this error.
2)  The affected feature layer still appears to load and function normally within the web app, and html requests show valid information.  It's only JSON requests that appear to be affected.

Does ArcGIS 10 require additional setup in order for JSON requests to work on a consistent basis?