Some online versions of mGBA aren't compatible with our conversion

[euan-forrester]

Example link: https://pegasus-online.pl/gry/gba/the-legend-of-zelda-the-minish-cap-pl
Example save state: Legend of Zelda, The - The Minish Cap (Europe) (En,Fr,De,Es,It) (PL).state.zip

The site appears to use EmulatorJS 4.0.5

This particular site allows users to directly download a save file, so it doesn't seem worth looking into further for now.

The offsets look a bit different: save size appears to begin at 0x61013 rather than 0x61004, and save data appears to begin at 0x61040 rather than 0x61030

[euan-forrester]

Although this file from the same site appears to not share the same offsets:
Pokemon - Leaf Green Version (U) (V1.1).state.zip

It's possible there's no save data in that file, since the user may not have known to perform an in-game save. But the save size reads as 512 bytes which is not correct.