I asked the same question on the Xerte Mailinglist.
Ron Mitchell suggested a solution. I post the reply of the Xerte Mailinglist here also.
Hi Ron,
Thank you VERY MUCH for your reply.
Uploading and displaying images by using a normal "graphics and sound" page doesn't work either.
The permissions on USER-FILES and underlying folders/files are
USER-FILES : 755 (or rwxr-xr-x)
2-name-Nottingham : 777 (or rwxrwxrwx)
2-name-Nottingham /data.xml : 644 (or rw-r--r--)
2-name-Nottingham /media : 755 (or rwxr-xr-x)
2-name-Nottingham /preview.xml : 777 (or rwxrwxrwx)
2-name-Nottingham /media/grootte_schakel.png : 644 (or rw-r--r--)
I have tried FireFox 36.0 (on both Windows 7 SP1 and Linux Mint 17.1) and InternetExplorer 11.
It doesn't work.
I have just tested it with Google Chrome 40.x and surprisingly enough that does work without any flaws.
This rules out any misconfiguration of the server.
So my guess is there is some JavaScript code that is specifically targeted to Google Chrome and doesn't work on other browsers.
The workaround you suggested with
FileLocation + 'media/grootte_schakel.png'
works also.
Thanks again for the fast reply and the solution for the problem.
I couldn't have found the solution "FileLocation + ...." without a thorough (and much time consuming) investigation of the source code.
Best regards,
John Bijnens