One of my BES users got an used handheld (from another user who got a new one) and he is getting an activation error i haven't seen before.
Afted completting the mail and password he initiates the activatiosn but, after just 5 seconds, he gets a "generic" error simply indicating "there was an error during the activation process, please contact the administrator"...
There are some more dialogs in the back but there is no way to see what they say.
The activation mail is not even sent, even tried with a GMail account to be sure it was not an antispam problem.
I checked the user account in AD and in BEs, the mail server and user mailbox permissions and found nothing wrong. The phone line is enabled for BB service in RIM and it has all the required categories on the HLRs.
There are no other users having activation errors, just this one.
Any ideas ?!

You say the device is enabled for BB service. Is it provisioned for BES service. BB service could mean just BIS.

Can you PIN to PIN or send a PIN to the device via BlackBerry Manager ?
Have you verified with the Carrier that the user is provisioned for FULL data plan ?
Are there any services in the Service Book area ?
Have you tried a FULL reset ?
Take a look in the Phone Call Log and see if the old phone number for the other person shows up as the phone number. If so, contact the Carrier.

Sounds like an incorrect password to me. If the EA fails within 20 seconds then the email is picked up and then the password is checked and then it fails.

Try using a lowercase 'L' or 'm' as they are almost impossible to get wrong. I'd bet any money it's a password issue.

Try taking the exact error and putting it into the search box here

PIN to PIN works and it has a full data plan. I don't know about the Service Books and we did try a full reset.
I used the lower-case "l" and had no luck, i even copied and pasted it....
The user has already sent the handheld back and he is getting a new one on monday. End users are not always interested in troubleshooting problems...

This must be the user with the worst luck of all !!
He got a new handheld and lunched the EA as anyone would. The activation mail got to the mailbox but the handheld remains on "Activating..." status.
BES is not picking up the activation mail, the user is able to see it in his Outlook Inbox... what can i do ?!

Ensure there is only 1 etp.dat attachment inside of their Inbox.
- If there are multiple, remove them all from the mailbox.

Make sure they are typing their password in correctly.
- if need be, just reset the password to "a".

Remove all etp.dat's, remove the user from the BES, have the user start the activation process with a password of "a", re-add the user to the BES, and set the activation password to "a".

I'm having the same issue, except my user is getting this immediately after starting the EA. It appears that it mentions something about a transaction error.. However I can not see the whole error due to "Contact Your System Administrator" dialog box.

I tried everything you guys sugested but nothing worked... :S
The user requested a new handheld, we'll see if it activates ok.

My issue was resolved when Sprint realized that something was not set correctly on the "BackEnd" of their system. However, my devices that were giving my EA issues where not able to do PIN to PIN messaging.