Cannot backup TDE Certificate

SQL Server Administration
1

I'm trying to backup the TDE Certificate but the OS reboots when executing the query:

BACKUP CERTIFICATE MyCertForTDE TO FILE = 'TestDB1_Cert.cer'
WITH PRIVATE KEY ( FILE = 'TestDB1Key.key',
ENCRYPTION BY PASSWORD ' TH!$IsN0TMyP@$$word'

And I get the attached error saying an unexpected error occurred during password validation.

SQL%20-DB13%20-%20error

I checked the Event logs after windows rebooted, and nothing in the logs even mentions that error, nor why
the OS rebooted. I checked the SQL error logs. No mention of a reboot, or the error I got. I checked "ErrorLog" in \MSSQL\LOG, and no mention of rebooting or the SQL errors.

The reason I'm trying to backup the TDE cert is because I need to move encrypted DBs to another server, and in ordfer to do that I have to backup the TDE cert, create it on the destination server, then backup the DBs and restore them.

Thanks.