One of my customers emailed in a panic (rightfully so), because they could not create a Quote from an Opportunity. When they did so, the following error popped up:
Actually, you have to hover over the error on the status bar to see it pop up.
I looked around for 30 minutes or so and could not see any issues recorded in any log that you might think of.
He had already restarted the SQL Server and I restarted IIS on the CRM Server but still the error persisted.
Having nothing left to do, I decided to look at the CRM services on the CRM Server. Sure enough, several were turned off.
Solution
Start/Restart all of the CRM-related services on the CRM Server.
I did a little testing and it appears that the Sandbox Service was the one directly responsible for the inability to add a new Quote, but just to be safe, I restarted them all.
This is a very fascinating situation and one that I’ve never seen before.