I guess this is due to the german local the program is running with: issue with "," and "." for numbers.
Unfortunately I do not know whether this concerns only the log or even the sent packets.
It is working great on uploading a single file, but when trying to split the file into chunks and upload them in loop (so each chunk as a file) it is not working but sometimes it uploads one chunk and the others usually I got upload file error = UPLOAD_ERR_PARTIAL
Is there something I have to add to the content or header?