That is a problem contingent on your emulator. The "in-game save problem" is usually the result of not enabling the right save type in your emulator settings. Since I am not familiar with your emulator, are there any settings that can be changed for it?
Also, every emulator have their own format of save states. VBA (VBA-M), you have to enable the following options in order to play this game properly: Real Time Clock (under "emulator settings") and save type "automatic-flash 128kb" (also under emulator settings). I hope this helps!
Tried al save options, but I still get the "save error"
This problem only occurs with this hack.
I have also tried it on my pc with the VBA emulator but same problem.
Not sure on what to try next.