Why does VBA crash when I try to load a save file?

I'm playing Pokémon FireRed on the VisualBoyAdvance emulator. I save via the emulator, and usually when I start the game, it opens my save directly, no intro or anything. However, I just tried playing Pokémon Emerald, and when I was going to go back to playing Fire Red, it didn't open my save. It's not in recent saves. However, it exists on my computer (Pokemon FireRed.sg1.SGM), and I can choose to load it... but then the emulator just crashes. I have not seen this before. Please help me get back to my Pokémon!

its simple problem with emulator or os and hadware if you use windows
i know there are emulators for linux and android but emulators often crash on windowses like 7
write what is your problem mean what message is show when emulator crash like:
directx.dll can be loaded etc...
try again run emulator and write again what is shown ok
then i and other users can help you

It just says "VisualBoyAdvance has stopped working".

so error is with your system try new version a clone:
https://sourceforge.net/projects/vbam/
if not helps change os (reinstall)
you can also instal vcredits and reinstal direct x
its a wayout but it not helps i
there is other way playing gba online
write name of game example : morning adventure gba online then you will have site where you can play the same goes with other systems like snes and nes
emulators often not work on win7 and 10 so i like old xp more on xp every emulator goes perfectly
but is so old decide play on xp on other pc/notebook play in gba on smartphone(yes emulators of various systems on android exists)
reinstal system instal updates vcredits ,dx9 or dx10 update all adio and video drivers
or just use other emulator
choose a one your choice
and one more thing other emulator is :NO$GBA

Did you update Visual Boy Advance and then try to load the save? If so you need to go back to the Visual Boy Advance you was using sometimes saves you made on older versions will not work on new updates.

No, I have not updated anything.

backup your save then delete Visual Boy Advance reinstall it maybe that will fix it.