One of the major advantages of the wiki are gone!
I have a problem uploading files in a wiki!!
With some wikis I get after selecting and uploading a file the message: uplrejsect.
What causes this behaviour and how to deal with it???
I have the same problem with some wiki's and therefore I can't use this wonderful module in my lessons 
I've just encountered this error. After a little experimentation - it happens when you follow a wiki link to create a new page and then immediately try and add an attachment. I expect what is happening is you're trying to attach a file to a page that doesn't actually exist yet because no changes to the new page have been saved.
Add something to the page, save it, re-edit and try it again. It worked for us.