Failed to find or load registered .Net Data Provider

Question

   `[HttpGet]
    [Route("allJobStatuses")]
    public IHttpActionResult GetAllJobStatuses()
    {
        //Getting exception here
        var allJobStatuses =
            DataContext.RefAllJobStatuses.Where(
                j =>
                    j.IsActiveFlag.Equals(DataConstants.True) &&
                    (j.Key.Equals("inprogress") || 
                    j.Key.Equals("completed") || j.Key.Equals("started")))
                    .Select(x => new { key = x.Key, value = x.Value });
        return Ok(allJobStatuses);
    }`

One of our Dot Net Project to which I recently joined using Entity framework using Oracle DB. But when I run application it breaks with an exception

"Failed to find or load registered .Net Data Provider".

I have installed ODAC with ODT, Xcopy ODAC all. I searched everywhere on the internet but none of them worked for me. I am not sure what to do.

Things I tried

1) Checking machine.config

2) Providing path in System Variables.

3) Checked Registry keys.

4)Checked DLL in GAC.

Please help me to solve my issue.