Design for scoreboard HELP!! (simulation error:Timestep too small)

hi guys, i have a problem with my design in multisim, I don't know how can i fix it without convergence assistant.
I'll just follow this design i have created and I'm worried if this design would not work in actual. Can you help me fix what's wrong with my circuit? Why does it gets simulation error: timestep too small?

thanks for that but I need an explanation based on my schematic diagram

It's difficult to know the problem just from looking at the schematic. Does it say anything besides "timestep too small".

Noticed--

U8, pin 8 is missing GND connection..

eT