I've tried to set up a kodi box to be as simple as possible for my grandmother to use. It works perfectly when I am there and I try to show her how to use it. But when I leave, she will call me and say that the context menu has appeared, and she has no idea what to do from that point. This was completely baffling me, because I had NOT mapped any buttons on the remote to the context menu, so I couldn't understand how she was possibly bringing it up.

After some googling tonight, I have discovered that flirc apparently maps a long press of the OK button to the context menu key. This must be how she keeps bringing up the context menu. Is there any way to disable this? She doesn't have good dexterity, so a quick press is difficult for her.

It's Kodi. They do that. Not me. I wish I had long presses finished....

You can look at this thread on Kodi forum: https://forum.kodi.tv/showthread.php?tid=260736. It shows how to disable long press by adding your own keymap file.

You may try using Kodi Keymap Editor add-on: http://kodi.wiki/view/Add-on:Keymap_Editor. I'm not using it so it's up to you to find out how to use it.

You can also look at this xml: https://github.com/xbmc/xbmc/blob/master/system/keymaps/keyboard.xml. This is a default keymap file. If you look for word "longpress" you'll see that it is used as a key modifier. That way you can find all buttons that are long press capable and also disable them if you use them with your remote (there's no need to override if your remote doesn't use them).

Thanks for the help folks! I had read some things that implied that this function was a part of flirc, but it looks like it is indeed Kodi. Seems easy enough to fix. Much appreciated!