AppCode 2017.1 stick "indexing"—but doing nothing

I have a problem where AppCode claims to be "indexing" but yet is actually doing nothing, but there is no symbol resolution, code navigation, etc. possible at all. Details are on this YouTrack issue: https://youtrack.jetbrains.com/issue/OC-15427

I'm currently working back in Xcode as I cannot make AppCode "wake up" despite deleting caches, rebuilding projects / workspaces / rebooting, etc. Problems started after I imported settings (exported from AppCode—same version—on my iMac to my MacBook).

Does anyone have any suggestions—apart from ditching AppCode?

Thanks,
Stuart