Page becomes empty when editing

[Michaël Goossens]

When tyring to edit a page, which has quite some content already the edit view only briefly shows the content of the page and then turns blank. Only the title remains. We can not alter the existing page anymore. Other pages still work as expected.

What can cause this?

[Brant Schroeder]

Often this is caused when the page becomes corrupted with some bad content.  Sometimes this is caused by a macro or content that was pasted in from a different web page.   I have seen this fixed by restoring an old version or creating a new page and coping the content into it from the page when it is not in the edit mode.