HOAB

Problem :

I was looking why my multipart header was not sent when suddendly, JMeter sends my POST HTTP request in a raw format.

Although I have in my GUI HTTP Request sampler a normal list of parameters : param1=value1, etc..., it sends

param1param2

Solution :

No solution on google, but it was "simple" : in my default HTTP Request, I changed the sheet "parameters" to "body data", even if the both was empty it was sufficient to invite chaos...

The first problem was that my Multipartform-data header was not sent : because a default one was set on default HTTP Header...

End of day....