they are marked as deprecated, but actually removed for 2015r2.
For all other plugin developers: Don’t use them.
Switch to register them as part of classes or modules.
same for REALFolderItemFromPath which I don’t use any more.
Those functions should still work, though I don’t recommend using them (hence the deprecation).
CallResolver gives NULL pointer here for those.
Earlier today I just run a quick test doing all CallResolver calls in the SDK and logging their result.
REALRegisterEnum and REALRegisterStructure have nothing to do at runtime, so the resolver returns NULL. REALFolderItemFromPath only is present on Windows and Linux.
Ah, thanks for clarification.