Not sure what your comments about 3.3 or 5.5 are
Did you overwrite your config file and maybe put wrong wrong information.
The error you put is pretty straight forward. Basically it says your photopost database name is warofthe_photopost and your table prefix is photopost.
Therefore it can not find a table in the warofthe_photopost database called photpostusers.
So based on my observation of your error what is your problem? If photopost is correctly installed there should be a users table so is your database name wrong or is your table prefix wrong in your config-inc.php file?
Basically you must ensure the database and its tables exists and you have the proper information for that database in the config file for you to upgrade and things to work right. If this was a functional install before you upgraded and you followed the upgrade documentation you should not have any issues.
Basically now we just need to track down the problem based on the errors posted.