RESTClient mit SSL

[Kas Ob.]

JSON in its standardized format doesn't have line beaks or spaces outside names and values ("").

While HTTP 415 is telling you the media or in this case the payload unrecognized format, so most likely and i am guessing here, Memo1.Text does have a valid JSON but not formatted correctly like it is beautified just like the your data content above or written over multiline, meaning you need to compact it also make sure it is trimmed before sending.