After adding a new system I can no longer see any data entered in the old system

ok, so i have a problem. I wanted to add a second system and since then I no longer see any data on my old system. Does anyone know how that could be? The two systems are probably in each other’s way. How can I completely delete the new system and try again?

Goto your account settings and at the bottom of this page there will be a list of all your systems.