Similar errors in text documents I saw were related to some kind of corruption of the content.xml that must have occured during a ‘Save’ or ‘Save As…’ run. I cannot really think of a way to get this fixed without analysing the content.xml with the help of an XML editor. As you already made a step in that direction you may try to identify the quoted part as an illegal redefinition of a property and to simply delete the illegal part (from the start of the quoted string till in front of the next “/” e.g. - but this is nebulous, of course) before wrapping the edited content.xml back into an ods. (You will surely be thorough about backups.)
Did you already try to open the file with different versions of LibreOffice? What about the recent 5.0.0?
Supposing you are on Win: You won’t want to change your installation for experiments, but you can get the most recent released version V5.0.0 and many old versions, too, as a portable variant in a .paf.exe package from this location e.g. These packages will expand an can be used (deleted later-on, too) without an installation.