This error message pops up when opening a document in LibreOffice:
LibreOffice 3.5 Read-Error. An unknown error has occurred.
I can, however, open a fresh new document. This is obviously not desirable behaviour.
EDIT: I tried opening a Calc doc which I used in my 11.04 installation (which is now 12.04). The documents are as they always were, in my Documents folder. Impress files seem to open fine. I've not yet tried a Writer file yet, as I don't use them too often.
What is the problem?