For some reason you put your database in SINGLE_MODE.
ALTER DATABASE fbDataCollector SET SINGLE_USER WITH ROLLBACK IMMEDIATE
After a while you realised that you can not bring it back in MULTY_USER because you have been locked out of your DB.
One option is to find the SPID who is using it, kill it and then bring it back to multy_user.
— the following query lists all database sessions
select d.name, d.dbid, spid, login_time, nt_domain, nt_username, loginame
from sysprocesses p inner join sysdatabases d on p.dbid = d.dbid
where d.name = ‘DBNAME’
— kill session using SPID number
exec sp_dboption ‘DBNAME’, ‘single user’, ‘FALSE’