Marten -
The XD Image Loader code has actually been broken since V8.5, but since in V8.5 it wanted to load 8.5.0 maps and the default value of fixpack level (if it's real value isn't found) is '0', everything worked OK. But in V8.5.1 the XD Image Loader's broken code still wants to to load 8.5.0 maps, so it doesn't work so well.
I have attached a patch (a bit different from what will be in V8.5.2) to 2 methods in the AbtServerDevelopmentApp. After the patch is filled in, you need to execute:
AbtServerDevelopmentApp register
John