I have a client that was getting Error 0x80044005 this morning.
The SQL server is seperate from the CRM Server.
Event logs did not say much. The above error number is 2.
I checked the Database server, opened up SQL Enterprise manager and found
that two of the CRM Databases were set to single user mode.
If you have this problem just Right client on the Database. Goto Properties
and then the options tab.
I found that the "Restrict Access" Box was checked. So I unchecked it and
then restarted the CRM and Crystal Services on the CRM server.
Now the question is how did just two of the databases get set to Single user
mode during the weekend. The Database Maintenance plan should not do that,
but it turned out that manual backups were made on the databases.
Anyway, I hope this helps someone.