May be a little late - but did you check that SQL Server Browser was running.

I had same error message and starting that resolved my problem.

Last night I hit exactly the same issue.

Previously I had SQLServer 2014 dev edition, SQLServer 2008R2 Dev Edition

Upgrade from windows 8 to 8.1

When tried to connect through SSMS - every...

Thank you for the LSN explanation re the proprietary software - that makes sense to me.

But I don't have any access to the log file backups, the database...

Thanks for the feedback Perry, Grant, TripleAxe

They're using : Dell Netvault Backup

One example db log is

allocated 30436.56 MB, available free space : 30301.75 MB (99%)

Last DB Backup is showing 04/12/2014...