With the release of CaraVR 1.0v4 there is now a compatible release of CaraVR for Nuke 10.5.
This article explains why CaraVR 1.0v1 to v3 were not compatible with Nuke 10.5 releases.
Due to changes in the Nuke NDK (Nuke's C++ plug-in API) between between major versions of Nuke, NDK plug-ins such as CaraVR and Ocula compiled for one major version of Nuke will not work with a new major version.
This meant that CaraVR 1.0v1 to 1.0v3, which were originally released for Nuke 9.0 and Nuke 10.0, were not compatible with Nuke 10.5v1 when it was released at the end of 2016. Attempting to load one of the CaraVR 1.0v1-3 nodes into Nuke 10.5v1 will produce an error message.
CaraVR 1.0v4 was released in February 2017 and includes support for Nuke 10.5, Nuke 10.0 and Nuke 9.0. Download links for CaraVR are available from the CaraVR downloads page.
NOTE: This issue affects other NDK plug-ins as well and is explained in the following article: Q100234: Will plug-ins for NUKE 10.0 work with NUKE 10.5v1?