Well, you can not just move a site to a new server. Never works. And, moving a forum site to a new folder never works either. I will give you some ideas why they do not and then how you might solve it.
All forums use pointers to steer every single page in the forum to the correct pages needed in various folders and sub-folders. So, when moving from one folder to another, it can be done, but, you must know how to change the pointers built into the forum software. (phpBB is easy and more info on that below…)
Next, since forums use database which are set up in very specific ways, you normally can not move this layout to a shared database unless you have a way to keep your data separate from the shared data. So, as example, if you have phpBB and when you set it up, you used a prefix of “phpBB_” for the database tables, you would not have any issues as they could be the same on the new server. But, since you let someone else handle that change, it is hard to say what they did. Using the phpbb_ as a prefix is the standard install for this forum software. You can see a list of them here: phpBB Tables List
So, first step is to log into your old server’s control panel and bring up your phpMyAdmin page and review your phpBB tables. If they look like the ones in this link just posted, they are standard. Next, log into your new server’s control panel and the phpMyAdmin page and review the tables in your new database and see if they match. If they match, you are all set for this part. If not, you will have to fix the names the hosting company used when they copied your database to their shared version.
Lastly, you will need to fix the pointers for where the forum code was stored into the new folder layout.
I looked around for you and found it was easy to do. Here are the steps…
Log into the phpBB’s Admin Control Panel (ACP) ( On the new server, of course! )
Select the Server-Settings
Select the Script-Path
Change this pointer to the new path to the new folder
And, that should re-link up all of your scripts correctly. After that you should be in business!
Good luck, and let us know how it goes!