Created question in FIWARE Q/A platform on 29-06-2021 at 15:06
Please, ANSWER this question AT https://ask.fiware.org/question/1253/error-in-ngsi-source-operator-exception-catched-while-processing-preference-changes/

Question:
Error in NGSI source operator: "Exception catched while processing preference changes"

Description:
I am new in Fiware and I am doing a tutorial to configure a map widget. I run Wirecloud following the section "Running Wirecloud" (https://wirecloud.readthedocs.io/en/s...)

On the one hand, I have followed the steps in the section "SANITY CHECK PROCEDURES", but although the web map service is visible and I can mark a point, in the weather widget nothing is visible (It stays loading).

I have tried to configure the operator but I don't know how I can know which is the NGSI Server URL.I have write: http://localhost:8001 because my Wirecloud port is 8001.
In Wirecloud, I can read this information about the "NGSI Source", but I don´t understand the meaning of this:

NGSI server URL: URL of the Orion Context Broker to use for retrieving entity information.
NGSI proxy URL: URL of the Orion Context Broker proxy to use for receiving notifications about changes.

On the other hand, I have tried to put other widgets and operators that appart from the NGSI server URL they need the NGSI Proxy URL, and I don´t know how I can have this last one. I tried to do this https://github.com/conwetlab/ngsi-proxy to configure it.

Thank you in advance.