XBMC releases are brought to a stable point where most users should not have issues. However, due to XBMC's large, complex, and multi-platform nature, it is nearly impossible to release a totally bug-free version. As such, these are some of the more common issues that are known about in XBMC.
- When using UPnP library sharing between XBMC instances:
- The watched/resume status for TV shows/episodes doesn't always update right away on the "client" XBMC instance.
- If you have a TV show that has watched episodes and unwatched episodes, the entire TV show will be hidden if "hide watched" is turned on.
- Chapter markers for MP4 files are broken in v13 and v14
- Mplayer style EDLs (.edl) don't work well when stepping back or forward in v13. 
- Using variable rewind (x2, x4, x8, etc) will actually go faster than it is supposed to. A fix has been done but won't be ready for v13:  (however, it is fixed in OpenELEC)
- The current AFP client in XBMC is unstable and will eventually be removed.
- A minor cosmetic flaw, when a single TV show is created from more than one source path (like some seasons on hard drive A, other seasons on hard drive B) certain counts in the GUI (i.e., number of episodes) can be off. 
- Default touch screen skins (iOS and Android) do not have Live TV/PVR support yet.
- Non-XBMC issues
- AirPlay Mirroring and any AirPlay function that involves DRM is not supported
- Some Amlogic-based Android devices have issues playing back video. This will be fixed in the upcoming v14.1 bugfix release: http://forum.kodi.tv/showthread.php?tid=213108
- Some x86-based Android devices don't work correctly with v14. This will be fixed in the upcoming v14.1 bugfix release: http://forum.kodi.tv/showthread.php?tid=213108
- The CTRL modifier for keymaps currently doesn't work. Other modifier keys do still work.
- Initial Android support is targeted at inexpensive Android powered set-top boxes. As such, support for mobile devices is still being developed, but will improve with time.
3 Linux general
- Ubuntu might "steal" media keys (play, fastforward, rewind, volume, etc) before Kodi receives them. A temp work around is to un-set these keys in Ubuntu's keyboard shortcut settings.
3.1 XBMCbuntu specific
- All AMD/ATI users with a GPU up to ATI HD5xxx will have a failed install because 12.10 does not carry compatible fglrx a workaround is on this thread.
4 Mac OS X/iOS
- Gapless playback for music isn't working.
- Non-XBMC issues
- Apple does not provide support for HD-audio passthrough in their audio API, CoreAudio.
4.1 Mac specific
- There seem to be some audio sync issues when refresh rate is changed to 24hz.
- No retina support yet.
- Some tools/applications which adjust screen brightness may lead to low framerates (5fps framerate limiting) in XBMC. The most common ones should be exempt from this and not cause any issue, but there may be others. Please report any tools/applications that still have this issue to the XBMC support forums so that we can add them to the exempt list. (basically all tools which use a transparent fullscreen overlay)
- Certain Macs using Intel GPUs seem to show a green line when using hardware decoding (VDA). A fix was found, but that fix caused some other issues, so the lesser evil was chosen (green line). Developers are still working on this issue. In most cases the Mac in question can run just fine without the hardware (VDA) decoder, as they have more than enough CPU power. It won't hurt anything. At most it might just kick up your CPU fans more, depending on how demanding the video is. You can turn off hardware video decoding by going into Settings -> Videos -> Playback and deselecting the VDA option.
4.2 iOS specific
- Cydia will still show Kodi v14.0 as having an update available even after it has been installed.
- Retina support for iPad is currently GUI only. Video resolution currently maxes out at 1024 x 768. Retina is fully supported for iPhones and iPod touches.
- Non-XBMC issues
- Apple TV 2 will crash on startup when older versions of Plex are also installed. Either uninstall Plex or update it.
5 Raspberry Pi
- None currently with Kodi v14.0 Helix
- AirPlay videos recorded with iPhones/iPads might not rotate correctly when using hardware video decoding 
- Windows screensaver and power saving mode kicks in when XBMC is not focused (independent of whether XBMC is playing a video or not)