[8FS_Bulau]

I have 4 buttons files and i'm not really sure which is being used. They are:
(1) stored at ...JSGMEMODS\zHSFXSwitcher\.... ------ 1118 kb
(2) stored at ...JSGMEMODS\zHSFXAlternateFMs\..... ------ 1648 kb
(3) stored at ...FILES\GUI\GAME\ ------ 1683 kb
(4) stored at ...MODS\STD..... ------ 1689 kb

(4) will be used if the MODS folder is activated (without minus sign)
(3) will be used if MODS folder is inactivated (rename with minus sign)
(1) will be used if you use the JSGME and activate Hsfx History Mod
(2) will be used if you use the JSGME and activate the alternate FMs

That said, I've only seen this error associated with Tiger's Sound Mod, which adds a lot of bits into the Files folder. I'm not that familiar with the Tiger Mod, but it may come with its own buttons, too.

In any case, I'm not sure this has anything to do with buttons. I think it is something in that mission which you are missing, or rather something in that mission is missing something...

From a thread over at SAS:

Guys,answer for that _CanonDump01 error is simple: one or more moded aircraft you got instaled has weapons using shells effect for its guns,but meshes(fuselage or wings) lack _CanonDump01 Hook for them,thats why game cant load those effect properly and give a console error,and prevent mission from loading.To solve this you must first knew wich aircraft cause this error,this should be simple just check what aircraft is used for that mission , than (this could be hard part) ask its creator to fix that bug by adding missing Hook to proper mesh:

[Hooks]
_MGUNXX gun flash
_MGUNDumpXX shells effect

You could probably fix it by loading that mission (if you know where to find it) into the FMB, then save it. That might replace the problem aircraft (which probably predates the mod pack you use) with whatever is in your mod pack. No guarantee, though...