404 error trying to access admin after upgrade attempt

[sewnsails]

A critical server error triggered while attempting upgrade. Now I can't access admin panel. I get a 404 error when I try to login

[timlight10]

What version of AbanteCart?

[sewnsails]

I believe I was installing 1.4.1

[Basara]

I believe I was installing 1.4.1

Hello.
You need to locate the error log file and check the exact error that caused the upgrade to fail.
Alternatively, you can restore your store from a backup and try a manual upgrade:
https://abantecart.atlassian.net/wiki/spaces/AD/pages/5275676/Upgrade