Stuck on V1.11.0 on WRT1900AC V1?

[RichMD]

I have a Linksys 1900AC v1 and installed 1.11.0 a while ago. I recently wanted to try DD-WRT or some other options. I found that even though I loaded a stock Linksys firmware or a DD-WRT version, etc. nothing makes a difference. It never completes and upon reboot, I am still on Gargoyle 1.11.0. I tried a reset via the button and a 30-30-30 reset which did reset to the default values and then tried a firmware update again but nothing changes. It seems like the firmware upload doesn't work. Any thoughts on how to fix this?

[Lantis]

Check out the wiki
https://openwrt.org/toh/linksys/wrt_ac_series
Particularly the section on returning to OEM where it says it must be done from the command line.

Don't go directly to ddwrt, go via OEM first.
And 30-30-30 reset does/did nothing. Any perceived benefit came from something else.