I already typed this once and it was erased, so fix my problem. I did everything you already suggested on every forum you publish and it does not work. I use 4 Roku Express and none will update. My solution will be to buy firesticks and destroy them, if no answer, and will hit every website with my complaints with the facts.
The latest update - 12.5.5.4174 - is broken - once installed the 3930x does not work.
Thus it is probably good that you cannot upgrade.
Perhaps Roku have withdrawn the broken update until they can produce one that works ?
We’re upgrading Roku Community to bring you a faster, more mobile-friendly experience. You may notice limited functionality or read-only access during this time. Read more here.
Planned Downtime:
Community will be unavailable for up to 24–48 hours during the upgrade window during the week of May 19th and you may notice reduced functionality.
In the meantime, for additional assistance, visit our Support Site.
We're sorry for this disruption — we’re excited to share what’s next!