Your error has nothing to do with this thread.
When you installed Photopost from the error you posted it looks to be if the database information you entered is correct to connect to the
VB database then in the next to last step you did not enter a table prefix
You can use phpmyadmin and view the settings mysql table of photopost and edit line 83 and set the setting to your vb3 table prefix entry which is found in your vb3 config file in the includes directory