One more thing, EM uses tempdb for this so if tempdb is extremely busy, timeouts will occur.
"There are two ways of constructing a software design. One way is to make it so simple that there are obviously no deficiencies. And the other way is to make it so complicated that there are no obvious deficiencies."
"If you think it's expensive to hire a professional to do the job, wait until you hire an amateur." Red Adair.