Your comments

It is for webdav  access to a confluence wiki server run by a university. (UM med school)

The program crashes the moment you try to navigate to a directory with a space.  As long as you touch directories with no space you can keep navigating the tree and open text files within in them.

For what it's worth, I can navigate the same directory tree in GoodReader using the webdav connection, regardless of the presence or absence of spaces in directory names.

 I did find an advisory in the institution's help pages which may make you feel like not investing too much time looking into it.
"WebDAV integration isn't working very well with Confluence at the moment. There is an issue with the way that the Confluence WebDAV implementation interacts with the Netscaler appliance that placed in front of all UMMS applications. This message will be removed once the issue has been resolved."
But as I say it works fine with GoodReader which is why I asked if there was a simple explanation, as it does make the app somewhat less useful to me.