Freedom "{"error":"The uploaded content did not match the .png file extension.","ns":""}
This is DW telling "The file has .png extension, but the content is not valid png". For me, the png file is not a true png file.
As I'm not a windows user, I don't recognize the "properties" capture you added. What software is this ? I'm a bit puzzled by the "ZIP compression" and the 2 file sizes 3 072 and 2 440 bytes. Maybe this is perfectly normal and I just don't understand what I read, or maybe there is something happening here. @louis-ouellet asked but you did not answer. Can you upload the file somewhere so we could inspect it ?
If you are sending zip compressed file, no wonder that DW rejects them.
Here is a simple png, 32x32 pixels. https://ohk0maingahghiethaebie0aegeowiek8xah.bidule.https443.net/p00/4LJhPE-32.png. If you download the file on your computer and then try to upload it to you wiki, does it work ?