Hello, the release notes document indicates that it must be updated to version 200.7.10.202.94, in order to update to 200.8.10.3.243
NOTE
To upgrade to 200.8 using the online upgrade method, your Unleashed network must be running 200.7.10.202.94. If
your network is not running this version (200.7.10.202.94), please upgrade to this version firts.
Regards