I'm having the same problem now. been trying for 2 hours to get it to update, it starts downloading, but when it gets to 54%, it stops and then says it is unable to update software.
The Roku SE was discontinued years ago. It is still officially supported, but if it's now beginning to show issues with updating, it may be reaching end of life. I'm not saying toss it, I'm just tempering your expectations.
If it's hanging up during an update, a factory reset may be in order. Press and hold the Reset button for at least 30 seconds. You'll have to re-link the device to your account, since it will go through the initial setup following a factory reset, but once that completes, it should be back to normal.
Again, it may be time to update your nearly 8 year old device.
DBDukes Roku Community Streaming Expert Note: I am not a Roku employee.
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