Using Ubuntu 17.10 and Libreoffice I've updated everything today.  

Trying to open .od\_ documents from my /Documents folder now yields "Access denied" 
(see also question [[Access to \*.doc was denied | Libreoffice 5.4.5.1](https://askubuntu.com/questions/1008741/access-to-doc-was-denied-libreoffice-5-4-5-1][1])) 

/Documents in my case is mounted via NFS. 

Copying a document from the NFS filesystem to the local $HOME works and the copied document can be opened with Libreoffice.  

So the bug seems to affect only network or removable filesystems. 

Edit: Structured the question and moved the solution to a separate answer