I cannot open an .odt document with LO4 but I can do it with OpenOffice. If I save the document with OO then I can open it with LO. Is there a bug behind_
Reported as Bug 65521 - FILEOPEN: LibreOffice fails to open a .odt file, but OpenOffice does.
(Sample file in fdo#65521)
EDIT 2013-06-20
Status: RESOLVED WORKSFORME (v4.1.0)
OK for closing the subject
Which in common language means the bug is fixed in 4.1 (which will be released by the end of July, with release candidates already available)
I still have this bug in LibO 4.0.2, 4.1.5 and 4.2.1… Is it really fixed? Just crashes without error message, while OpenOffice can open it without complaining!
Edit: I’m using Linux Mint
@panos, I can open the file included in the bug report without any problem. If the bug still occurs under Linux Mint using the same file then Reopen the bug. If you are having the same problem but with another file, then open a new bug report.
I can open that file, too, so I guess it’s a different variant of the same problem… I’ll try to upload a version of my file. Also, is there a log file where I might an error message? I have already looked at ~/.xsession_error and couldn’t find anything relevant.
@panos, I have no idea 
Maybe some Linux user can help with that… Please create a new bug report at https://bugs.freedesktop.org/enter_bug.cgi?product=LibreOffice
Apparently it was some regression in LibreOffice. It is already fixed in version 4.1 (you can get a working Beta today or wait for a Release Candidate in about two weeks)