Topic: monitoring points for load reading value

Respected sir,
I am new to ATENA and currently i am doing project "two adjacent edge fixed supported slab carrying area load and line load (UDL) on its free edges" on ATENA 3d.  I have these queries:
1.  my both adjacent edges are fixed so do I need to fix the reinforcement bars from fixed end side or by fixing the macroelement surface can solve the issue?
2. I have assigned two monitoring points 1 for load and one for displacement but after analysis this message is showing "Monitor U2 - load: error reading value" and where to apply the monitoring point in order to get the total ultimate load?
please help me in this regard