I backed up a database:
BACKUP DATABASE MyDatabase
TO DISK = \'MyDatabase.bak\'
WITH INIT --overwrite existing
And then tried to restore it
I had a similar issue with restoring using SQL Management Studio. I tried to restore a backup of the database to a new one with a different name. At first this failed and after fixing the new database's file names it was successfully performed - in any case the issue I'm describing re-occurred even if I got this right from the first time. So, after the restoration, the original database remained with a (Restoring...) next to its name. Considering the answers of the forum above (Bhusan's) I tried running in the query editor on the side the following:
RESTORE DATABASE "[NAME_OF_DATABASE_STUCK_IN_RESTORING_STATE]"
which fixed the issue. I was having trouble at first because of the database name which contained special characters. I resolved this by adding double quotes around - single quotes wouldn't work giving an "Incorrect syntax near ..." error.
This was the minimal solution I've tried to resolve this issue (stuck database in restoring state) and I hope it can be applied to more cases.