Migrate config from 3600 to i4600

Hi, I did try that command, and the error I get is:

    Saving active configuration...
Current configuration backed up to /var/local/ucs/cs_backup.ucs.
Product : BIG-IP
Platform: UCS   : Mercury
          System: C115
Version : UCS   : 12.1.0
          System: 12.1.2
Edition : Final
Hostname: apl-amb-bigip01.x
Installing --full-- configuration on host apl-amb-bigip01.x
Installing configuration...
WARNING:
    This system's device certificate uses a key size that is considered insecure.
    It is strongly recommended that you use a certificate with a key size of at least 2048 bits.
Installing the license file...
ATTENTION REQUIRED:
   Your previous configuration files have been archived, as listed
   below. If you customized any settings in these files before
   upgrading, you will need to manually restore those changes by
   using the Configuration utility or Traffic Management Shell (tmsh).
   Archiving /config/wa/pvsystem.conf.12.1.0
   Archiving /config/wa/globalfragment.xml.12.1.0
   Archiving /config/wa/pvsystem.dtd.12.1.0
Post-processing...
usermod: no changes
Reloading License and configuration - this may take a few minutes...
Jun 28 19:59:41 apl-amb-bigip03 emerg mcpd[6445]: 01070608:0: License is not operational (expired or digital signature does not match contents).
Jun 28 19:59:53 apl-amb-bigip03 emerg load_config_files: "/usr/bin/tmsh -n -g load sys config partitions all " - failed. -- 01070307:3: Invalid interface 1.1 Unexpected Error: Loading configuration process failed.
Jun 28 19:59:55 apl-amb-bigip03 emerg load_config_files: "/usr/bin/tmsh -n -g load sys config partitions all base " - failed. -- 01070307:3: Invalid interface 1.1 Unexpected Error: Loading configuration process failed.
Configuration loading error: base-config-load-failed
For additional details, please see messages in /var/log/ltm

WARNING: There were one or more errors detected during installation.
         Check the error messages and take the proper actions if needed.
ERROR: UCS installation failed.
Operation aborted.
/var/tmp/configsync.spec: Error installing package
Config install aborted.
Unexpected Error: UCS loading process failed.