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.
- If you keep DVD rips in a VIDEO_TS file format, have "file deletion" enabled in XBMC (it is off by default), and delete the VIDEO_TS entry from within XBMC, you run the risk of deleting all of the actual video files in your library. 
- 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.
- 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 still the not-so-stable one from Eden.
- If you scan using the "NFO only/local info only" scraper, all sub-folders will be forcefully set with "NFO only" as well.
- 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. 
- Videos encoded with VC-1 and that are interlaced will not currently playback correctly in XBMC when software decoding is used.
- Video played in the pictures slide show won't work 
- Default touch screen skins (iOS and Android) do not have Live TV/PVR support yet.
- FIXED in future v13 Sometimes you have to force update add-on repositories to see a listing of add-ons.
- FIXED in future v13 Dolby Digital Plus support seems to have issues. Dolby Digital and Dolby True HD are unaffected. 
- FIXED in future v13 FilterSMS keymappings are not working in views that use the advanced library filter. The next version of XBMC, v13 "Gotham", will allow skin authors to choose between old style filtering or advanced library filtering. 
- FIXED in future v13 While TV shows and music videos have video library tags just like movies, smart playlists will not use tags as a rule. Movie smart playlists are unaffected by this. 
- Non-XBMC issues
- AirPlay Mirroring is not supported
- 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.
- FIXED in future v13 No hardware video decoding for most devices, which means no HD playback support unless there is a fast CPU. This is something that is under active development and will eventually be improved for a number of devices. See Android FAQ for more info.
- FIXED in future v13 Volume needs to be set high on the Android device before entering XBMC, as XBMC will not exceed this set volume level.
3 Linux general
- Non-XBMC issues
- FIXED in future v13 and via AMD OSS video drivers AMD GPUs do not support HD-audio passthrough under Linux
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.
- FIXED in future v13 AAC to AC3 transcoding is broken for the time being, which means no multichannel support for AAC.
- FIXED in future v13 Music output lacks "audiophile" support (output is resampled to the setting from audio midi setup for all tracks)
- FIXED in future v13 All sorts of hickups during music track transitions (gets worse with activated crossfade).
- Non-XBMC issues
- Apple does not provide support for HD-audio passthrough in their audio API, CoreAudio.
4.1 Mac specific
- Mac OS X 10.9 "Mavericks" has introduced a buffering/stuttering issue that seem to only effect certain Macs. Possibly related to the OSX AppNap feature.
- 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
- 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.
- Uppercased special characters with accents are shown as lowercase (when uppercase tag is used in the skin) (See here for a possible temp workaround).
- iDevices that use an A7 chip (64-bit) won't use hardware video decoding. Software video decoding should be enough to play back most videos, but will drain the battery faster.
- FIXED in future v13 iDevices with iOS 7 won't correctly work with video out cables or using AirPlay mirroring to ATV2/3.
- FIXED in future v13 iDevices with iOS 7 crash when using DVD menus.
- FIXED in future v13 Retina GUI is not enabled for v12 builds for iPad Air (5th gen) or iPad Mini (2nd gen).
- FIXED in future v13 12.1 only - There seems to be a memory leak with some add-ons in the 12.1 release that will cause out-of-memory crashes on some iOS devices such as the ATV2. If you are having these issues, you may wish to downgrade to 12.0.
- Non-XBMC issues
- Apple TV 2 will crash on startup when older versions of Plex are also installed. Either uninstall Plex or update it.
- iDevices will crash on startup if Display Out is installed.
5 Raspberry Pi
- DVD ISO playback is not expected to work well (there is experimental support with the hardware decoder in test builds).
- FIXED in future v13 Navigation sounds (clicks and such when you move around in the GUI) are not supported. Sound from music and videos are unaffected by this.
- FIXED in future v13 Playback of music from a USB CD drive might not work.
- FIXED in future v13 Fast forward/rewind do not, but "stepping" back/forward does work. In other words, the FF/RW buttons don't work on the On Screen Display, but you can go back and forward using left/right arrows (or whatever you map to stepping back/forward).
- Vista has a very strange bug that sometimes causes add-ons to give a "script failed" error. If you have this issue please report it on http://forum.xbmc.org
- 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)
- FIXED in future v13 The ability to select "OS default" for sound output in XBMC is missing.
- FIXED in future v13 Touch screen support for Windows 7/8 mostly doesn't work for Frodo.