Huh? What the heck to you mean by micro-architecture? I suspect you would not have been able to install OMLx ROME on your computer if it were not x86_64. That would be the architecture.
As far as making a statement on what is the oldest cpu supported how would we answer that given we do not have access to every old hardware ever made? As a small group we only have access to the hardware that OM contributors own. Intel Pentium Dual CPU T3400 is what 2008 or older? It probably should work just fine if slow due to it’s age.
OK, that amounts to saying “It’s broke”, and we can not fix “It’s broke”. Please start a new thread about your specific issue with a descriptive title and enough information so someone could help you. You can find more about providing information for support requests here:
How to get better results when posting about problems
I do not mean to be mean or snarky, in fact I want to help, but we actually do need information to help users with problems.
FWIW: I do suspect KDE Vault is broken in OMLx. But no one can do anything without something to work on like Konsole output or logs. And for users please post all the output not the part you believe is important. You can’t know what someone else might need to know to help.