5.4.9 firmware upgrade fail

Model:
Peplink Balance 20

Firmware:
5.4.7 build 1648

This is what I get

<response>
<status>0</status>
<errorMessage>Problem preparing for firmware upgrade. Please try again later.</errorMessage>
</response>

Please open a support ticket via our website and we can take a closer look at your case:
http://www.peplink.com/contact/support/

because I opened the ticket and I’m still waiting for reply, I decided to figure out, since I had the firmware version 5.3.12 still in the firmware partition 1, I changed to boot from that version and then it let me upgrade up to the 5.4.9 version, the release note mention something about that, but I was kind confused by the use of the word UPGRADE rather than DOWNGRADE (we going to an older version right?), I lost partially the configuration after reboot, but fortunately before a firmware upgrade PEPLINK reminds you to backup the configuration before, I did that, then I restored it and now everything work exactly as it was, as this issue was solved please you can go ahead and close the ticket #735347 for me.

Thank you very much

Manuel