I uploaded some trackmap images and wanted to put them on http://en.lfsmanual.net/wiki/Tracks:Rockingham

But when I edit the placeholder filenames, for example:
|Trackmap=[[Image:RO1.jpg|300px|none]]
to
|Trackmap=[[Image:RO1-Pits.png|300px|none]]
then the preview button returns a blank/white page. Submit-button also returns a white page and edits are not saved.
Otherwise editing seems to work, for example other pages or editing the text.

https://www.mediawiki.org/wiki/Manual:Errors_and_symptoms#You_see_a_Blank_Page