NuGaSa can't restore

Hello everyone
Recently I've been experiencing some problems with NuGaSa
I can backup my Gamecube saves but I can't restore them
anyone knows what's the problem?

Thanks in advance

Additional data:
NuGaSa: latest version
System menu: 4.1
HBC: 1.0.6
Bootmii: boot 2
Memory card: A Third party one that looks almost like this one (the only difference being that mine says "gamers" instead of "GC..."