Do you have a previous save I could look at?
I took a look at the save you uploaded, and the size was incorrect, and one of the blocks were blank.
This is the block that was corrupted:
I did manage to restore it using a donor block from my save, but given the block is named 'Game State', I'm afraid that the your story progression and game details would look wildly different.. thus it would be good to get a previous save of yours, this way, the progression leap you'll have to make won't be too huge.
Pokemon - Emerald Version (USA, Europe).sav