Documentrs not opening onth the desktop for editing

I don't use Microsoft word I use ODT.  After nearly six months  of the system advising I needed to install a tool box for  editing in the past two months BOX has opened ODT files to my desktop and I could updte and save in Box.  Then just in the past week that ability has gone Random, only allowing me to open some documents and not others.

All documents are uploaded in the same way, so what uptes may have been done that would cause BOX to stop downloading to mt desktop.

I have two colleagues in my organisation I need to share documents with and they can't edit either.  Can you please help?