I am running firmware 8.5.1 and experienced a system lockup on my Balance 310-5G yesterday requiring a power cycle to fix. It was in the middle of a live event with many devices being affected. I have logged a ticket for assistance.
I have tried to downgrade to firmware 8.3.0 but receive the error message ‘invalid firmware image’. Any hints here on how to resolve?
What firmware is everyone else running that is reliable and experiencing no lockups or overheating?
Thanks,
Andy.
Support has given me a fix (8.5.1s053 build 5992) to download via: https://download.peplink.com/firmware/epx/fw-epx_mbx_sdx-8.5.1s053-build5992.bin. I will report back in time.
I am running special build 8.5.0s053 build 5913 and have 2 months 27 days uptime on two devices with no recurrence of lockup. I continue to monitor.
Thanks for posting in relation to this.
@AndrewBourner we just had the same issue on a live event with B310-5G and FW 8.5.1 build 5955.
I am not sure if we should upgrade to the special fw mentioned above or directly to 8.5.3?
Hello @meb ,
Based on our experience, you need to be on either the special release mentioned above (8.5.1s053 build 5992) or the new firmware release 8.5.3 GA. Both these versions have been stable for our customers on the Peplink Balance 310 5G.
Happy to Help,
Marcus 
@mldowling thx for the reply. we’re still live so i hope the best for the next hours. than we will update to 8.5.3.
@meb I can confirm 8.5.0s053 build 5913 has been stable for my customer’s deployment.