Hi @Cynde_Moya - for the Game Boy Advance environment, I can at least confirm that cartridge images should be uploaded as “Floppy” type to work with Visual Boy Advance in EaaSI. So we can at least narrow it down there.
Are you uploading your .GBC file as a Content or Software resource? There appears to be an issue with the Software archive in the hosted service which is affecting a number of features, we’re investigating (Deleted resources still searchable (and selectable); Saved environment not loading)
If the file is still not running as a Content → Floppy type resource, can you please provide any more details from the error screen?