Cannot access the panel: ERROR: SWKeyExFatalError

[HoracioS]

Since the last microupdate, I got the following error when access to the panel:

ERROR: SWKeyExFatalError
xmlrpc error: Not valid XML. XML parsing failed

Is running Plesk 12 mu#10
# uname -a
Linux xxxxx.net 2.6.32-042stab092.3 #1 SMP Sun Jul 20 13:27:24 MSK 2014 x86_64 x86_64 x86_64 GNU/Linux

Regards,
H S