Could not load file or assembly ‘Oracle.DataAccess’

Here is the error I was receiving: Could not load file or assembly ‘Oracle.DataAccess’ or one of its dependencies.

Below are a few links to help out if you are receiving a similar error. But first, here is how I solved the issue.

In IIS go to whatever the app pool that running your website, click on "Advanced Settings", the set "Enable 32-Bit Applications" to True.

I found this answer here.

This site may also be of some use.

Hth.