Hello @gnothom
You haven’t advised which REST API endpoint you are sending the request to, but based on your sample request containing an ADF formatted description field body, can it be assumed it’s a Jira v3 REST API endpoint?
You haven’t provided any information about what this ‘dynamic payload constructor’ does, but can it be assumed it somehow takes the text typed by the user into the form field and converts it into ADF formatted text in JSON?
You haven’t provided any sample of the text created by that ‘constructor’ for anyone to determine one way or another whether the ADF content for the description field is or is not ‘funky’.
What, specifically, throws this error and where does it get displayed? The v3 endpoints return numerical, 400 series errors and I’m not aware of any v3 endpoint returning any error text that contains the phrase “Invalid Character”
With all this information missing from your question, all you’ve done is make a problem statement. Refer to the How to ask a good question thread for guidance on an acceptable level of information.
PS. In your sample request, I can see at least one mistake. For the paragraph’s content object, the text sub-object is not wrapped in inverted commas, so if the text from the user contained a comma, that would immediately break the JSON structure.