Field extraction receiving error message

[atatistcheff]

Any time I try using the Extract Field option in an event list the next page returns this error:

Error in 'rex' command:

The regex '//' does not extract anything. It should specify at least one named group. Format: (?...).

This used to work but it's been a few months since I tried it. I'm not doing anything special as you can see. The regex is just // yet it returns nothing. I tried restarting Splunk but I think something is broken somewhere.

[atatistcheff · Accepted solution]

I found the problem, there was a field extraction saved with just // in the regex. Not sure how it got there or why it was screwing up the extract. Deleting this extraction fixed the issue, I can now proceed through the wizard to extract additional fields.

[woodcock]

Great job! Now come back here and click Accept on your answer to close the question.

[atatistcheff]

Thanks for the answer but I have no way to mention a field name. To be clear, all i'm doing is clicking the Extract Fields option in the event and getting an error. Please see the screenshots below.

[uagrawal_splunk]

The screenshots are not attached.

[atatistcheff]

Sorry, I'm not good at attaching. See if you can find them here.

[uagrawal_splunk]

In which Splunk Version you are getting this error?

[uagrawal_splunk]

According to me, you have to mention field name in rex, which you can use further,
like (?<Name>//)

Please refer doc for more info:
https://docs.splunk.com/Documentation/SplunkCloud/latest/SearchReference/Rex