Is SDK 0.5.0.1 compatible with Runtime 0.4.4?

This makes sense. Apps built with 0.5.0.1 require the 0.5.0.1 Runtime installed.

Thanks for the quick reply.

BTW this was not the case with the transition to 0.4.4 from 0.4.3. I would be good to know which SDK releases are backward compatible with older runtimes and which aren't. A line in the release notes would do the trick.

As for best practices for how to deal with this, it seems OculusWorldDemo in 0.5.0.1 puts up an error message "Unable to initialize LibOVR". Could be a line in the Developer Guide.

Yes, there is a note in the "READ_ME_FIRST.txt" included with the SDK.

If you have not done so, be sure to download and install the Oculus Rift Runtime from
the 0.5 dropdown at https://developer.oculusvr.com/downloads.

The Runtime must be installed before running any apps built using Oculus Rift SDK 0.5 (DK1 or DK2).

From the history, it is said about how long developers can expect a specific version to be supported.

While in development kit mode, we plan to support old side-by-side DLLs for at least two months, giving developers time to update applications. After the consumer release, we will update the SDK to version 1.0 and, going forward, will support released API versions for longer periods of time.