I created a custom extraction for a query string. However, when I run the test, I receive the following error: Context parameter 'parameterName' not found in test context. Have you seen this error?
A common error message. Several causes are possible from you question.
Check whether the context parameter is actually there, perhaps there is a spelling mistake where is is set or where it is used. In the log showing the error message, look in the Context tab which show all the context parameters. Also check in the Context tab of one or two later requests as it may be set but not where or when you expected.
Make sure you have actually saved the extracted value into the context parameter. That needs code like: ouro e.WebTest.Context.Add(this.ContextParameterName, theValueYourCodeExtracts);
Make sure the extraction rule is called on the correct request of the test and make sure that the correct context parameter is named in the properties of that call.
The error you show reports
parameterName not found and that looks like a default name for the field, not a name that would be used in a real test.