Cant Change Clock Period

Hello,

I've been using Altera Max-Plus II v10.2 for quite some time now.I recently realized that when i try to change an input in the waveform designer to a clock,it always defaults to 200.0ns.And i can't change it.I tried increasing the time range but everything other then 1.0ns ,it says: '2.0us' is not a legal time value.

So i cant see past 8 steps with my clock.

Is there anyway to fix this?

Regards,

Pual Ogretine