remember when you do updates it overwrites your htaccess file, if you had any special instructions in there you will need to redo them. 

also make sure you clear your cache 

let me know how that goes 

I didn't have anything custom in the htaccess and it's still giving a 404 after clearing my cache. I even checked with a snapshot tool and even it got a 404.

what does debug say

For that I just enable debug mode in the config and go to the main page, right?

yes sir

Still just a 404

i did find an article that suggested it might be the htaccess file.   So try putting your old htaccess file in place from a backup and (save the old one to _htaccess   

lets take this one step at a time, i will try to find more info while you do that. 

just remember the file name is .htaccess  (with a dot in front)

Ah, okay, the current .htaccess just had the rewrite conditions commented out for whatever reason...

so  your back up and running ?

Yup, just have having some problems with the domain move I just did http://www.oxwall.org/forum/topic/35403?page=1#post-143857

cool team we can mark this topic one as solved i believe

You should actually try taking backup before doing any update. I suffered with this issue but from now i have started taking backup before doing any activity or updation in my website. And yes i am usually taking backup from "Ahsay software" . I am basically using this software from long time and really satisfied using this software. If you want you can actually use this software. Leaving a link below just check: http://www.ahsay.com/...ay_products_overview

James, could you tell us please have you managed to fix the update issue ?

If it is still persist then please do the following steps:
1.   Open the admin panel and disable all plugins.
2.   Find the file /ow_includes/config.php and change the value of OW_DEBUG_MODE to true. See the tutorial here: https://docs.oxwall.org/plugin-tuts:enable-debug. ; After enabling debug mode please copy the actual error here.

And check the folder permissions. The following folder must have 777 permissions set recursively:
ow_pluginfiles
 ow_userfiles
ow_static

ow_smarty/template_c

And please specify  what version of PHP your server is running.