We are running SQL Server 2014 Enterprise and have recently changed to use the SSIS Oracle Source.

We are randomly getting the error "Failed to load OCI method: OCIAttrSet" when running our packages.
It doesn't happen all the time. It happened last night and it would have been 2 weeks since it last happened.
We never had any issues with the OLE source.

What could this be?

The server is Windows 2008 with ODAC installed.
I don't understand really why it would work 95% of the time but the other 5% fails.