ESRI ArcGIS Server Feature Service reader won't read feature type. Error - ArcGIS Feature Service Reader: Encountered an unexpected error. The error code from the server was '500' and the message was: 'Error performing query operation'. Details: ''

Hi @edwibberley​ a 500 error is a generic error so that doesn't tell us much about what's going wrong here. However, it could be that this is caused by the server having trouble handling the size of the request. I recommend reducing the number of Features Per Request parameter and see if that helps.

Hi @danminneyatsaf​, thanks for the prompt response. I tried that and it didn't fix the error. Do you think it is likely to be an issue with the layer I an trying to read from?

@edwibberley​ based on the fact that you're able to read two of the other feature services, I'm thinking it could be an issue with the layer you're trying to read from. I'd be interested in taking a look at the ArcGIS Feature Service you're trying to access. If you're not comfortable sharing the feature service here, then I recommend opening a support case and we can follow up with you there.

Hi @edwibberley ,

Did you ever get a resolution to this issue? I’m having the same issue. The workspace reads every feature of the layer then before it finishes it returns

“ArcGIS Portal Feature Service Reader: Encountered an unexpected error. The error code from the server was '500' and the message was: 'Error performing query operation'. Details: '

The only point of interest on this service is that it’s a read-only feature service with no version management

For anyone else that runs into this…

In my case it was something weird happening with the HA config of our ArcGIS servers, after a day it stabilized, and the feature service now reads without error.

Even am getting the same error :

ERROR |ArcGIS Portal Feature Service Reader: Encountered an unexpected error. The error code from the server was '500' and the message was: 'Error performing query operation'

Any fix for this? Any help would be appreciated.

Hi ​@laxmi_2590, if you’ve tried some of the suggestions above (such as reducing the number of Features Per Request) and are still running into that error, can you please share your feature service with us so that we can take a look? Feel free to submit it as a support case if you’d prefer not to share it publicly.  

I’ve faced this issue too.  I’ve often been able to decrease the number of features read/written and enabled asynchronous writing with a timeout of 300, but have never been able to identify the root cause. 

Decreasing the number of features greatly impacts the performance.  I would love more feedback on working around this issue too.