Failed to import system certificate after backup restore on ISE3.0

[ik4693001]

Hello,

Performed Cisco ISE upgrade on VM from 2.4 to 3.0 by re-imaging with ISO.  After build completion, applied Patch5, then restored DB from configuration backups.  Attempted to import system certificate that was previously exported from ISE node with private key before the upgrade  and  import failed.  Trusted certificates root and intermediate are present and correct, show "good status".  I was able to import trusted intermediate and system certificate  after re-imaging, patching  and prior to data restore.  However, after the restore from backups was done, the system certificate was gone and I can't  import  the system certificate back ( root and intermediate certs are still there in Trusted store). The import failed  with "Private key validation failed: Invalid password" error. As a result, I can't complete ISE3.0 post-installation.

Appreciate your help!

[balaji.bandi]

If you have taken backup with Key, check the key has any caps or other special keys :

some reference :

https://www.lookingpoint.com/blog/cisco-ise-3.0-major-upgrade

[ik4693001]

Thank you for responding!
The password for key encryption to export/import contained upper/lower case letters and numbers. Are there any characters will not be allowed?
I am able to import and export the system certificate using the same password on ISE 3.0 node prior to 2.4 backup/restore. Once the 2.4 backup/restore is done on this node, I am no longer can import this certificate back. Unfortunately, if I import the certificate prior to running 2.4 backup/restore and leave it on, for some reason the certificate gets removed during restore and then I have a problem to bring it back.
Can you please let me know what can I try to fix this problem?