I've used FCEU 0.98.28 for some time now, and overall I'm very pleased with it, but one thing has been bugging me:
When running a Lua-script, if the script tries to perform an arithmetic operation on a nil value, it will return the same error message on each and every frame. As soon as you click on "OK" to close down the error message, a new one appears. This makes it very hard to stop the Lua script because the error messages block you from doing anything else from the menu bar. An example of a Lua script that will give such an error message is:
while true do
local function displayer()
gui.text(128,128,c)
end
gui.register(displayer)
FCEU.frameadvance()
end
It would be nice if this error message included a button that instantly stops the Lua script.
Oh, and it would be nice if FCEU had a folder for Lua scripts, just like it ha for .txt-files for memory watch.
Keep up the awesome job! :)