Message : "I/O error 103"
followed by / or
Message: "List out of bounds (x)" , where x can be any index number.
If you have already installed key licenses in "drive:\AXNFZZ" folder look inside for "READ ONLY ATTRIIBUTE" in any SIMATIC key file. If any, remove the file(s) attribute or delete the file and reinstall as required. Any key file with this attribute activated inside the AXNFZZ folder causes EKBInstall to crashes. Automation License Manager (ALM) "finds" this installed keys as good but EKBInstall does not. Why? I don´t know, we should ask to the EKBInstall program developer!!!
Normal attributes for this SIMATIC keys files are: A: Archive, H: Hidden and S: System.
This is all for now, I hope that this post can help to somebody.

Regards.
PD: I don´t know if this procedure solve the problem in all cases and OS. W7 Pro (x86) and (x64), XP Pro (x86) tested.