There has been a massive problem with Photobucket since at least October 2016 and Photobucket doesn't seem either inclined or able to fix the problem.  People can't upload photos unless they do it exactly as this post (in a Photobucket discussion topic) lays out:

First just get into your account ( DO NOT UPLOAD ANYTHING AT THIS STAGE!)

(Note: the problem is that when you attempt to post photos, you end up in an endless loop of being required to log onto Photobucket, so the first trick is simply to log in, and once logged in, only post photos as described here)

Second, You should see just above your photos three boxes (WHATEVER YOU DO, DO NOT CLICK ON THE UPLOAD BOX). The first box (left hand side) says LIBRARY, so click on that.

Third, You will see all your photos with http addresses etc below each one. Now you will see that the very first box (right next to the first image says: CLICK TO UPLOAD, so click on that and you will then go to a window with all your files folders etc.

Fourth click on the image that you want to be uploaded, and wait for it to complete; yes, it pauses a t 90% but hang in there until you are able to see it in your photobucket account.

I hope this helps!

I'll try to re-word this:

Log onto Photobucket, and access the specific album you want to post to.  BUT:

Do NOT attempt to post photos with the button I've outlined in a red box here:


If you click on that box, you will be caught into an endless loop where you're constantly being required to log in again (and again and again)

Instead, click on the box I've outlined here in red, and post your photos one at a time: