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Panther Knowledge Base

What Does "Expecting value: line 1 column 1 (char 0)" mean in Panther Analysis Tool?


When trying to upload detections to panther-analysis-tool (PAT), you encounter the following error:

Error: : Expecting value: line 1 column 1 (char 0)


This error is usually indicative of a failure with the upload, but isn't descriptive of the precise cause. To resolve the problem, contact our support team. Be sure to include the following information in your ticket:

  1. What did you try to upload?
  2. How many times did you try?
  3. What did you change in your repo before uploading?
  4. Are there any other errors?


This error is caused by the PAT JSON parser which is used to deserialize the error response from your Panther instance. In some cases, the error response doesn't include any body text, which causes the JSON parser to panic before relaying the rest of the error info.