bookmark+ with remote server issue

[simonh]

I'm connecting to an Ubuntu server in Virtualbox (for learning
purposes), and I've bookmarked a directory on the server in dired.
Everything is working fine, except when server is powered off. Bookmark
+ won't display *any* bookmarks. I get an error message:

Process *tramp/ssh address@hidden exited abnormally with exit code
255

Of course I know that the server can't be accessed but surely bookmark
+ can display my other bookmarks? Is there a solution to this problem?

Thanks.