I just recently upgrade to MyBB 1.6.12. Well at first, I made a backup of my files so I can keep a copy. But, I downloaded the new package and wrote over my old files, and went to /install/upgrade.php and when it asked me which version I'm upgrading from, I couldn't see 1.6.11. I went back to your homepage where the mybb 1.6.12 news were and realized that I was supposes to upload the changed files package. So I reuploaded the backup and uploaded the changed files, but now when I try to view a topic it says, "404 Not Found". So I'm reuploading the backup now while waiting for your response. When I click on the topic, I get a blank page.
I am still having this trouble.
if you the followed the steps correctly you will have no problem
well I still am. Its still giving me a blank page.
Can somebody help me out? My forum has been closed for a couple of days until I fix it.
Apply changes to core files SEO Plugin !
I find this confusing. When you re-uploaded the backup, the first time - I guess, did you then have a functioning 1.6.11 forum? Then it changed to the 404s when you uploaded the changed files? Then you re-reuploaded the back up and now you get the blank pages? On those last two sentences it's not clear whether the blank pages came before, after or during the "reuploading the backup now".
It does sound like you may be using search-friendly URLs or an SEO package but have lost the .htaccess magic that makes it work. (ie all the mod_rewrite stuff in .htaccess.)
I had a functional 1.6.11. When I uploaded the changed files, I got 404 errors, and then I uploaded the backup and now I get blank pages.