# Problems with proteus simulation of register

I tried to simulate universal register in proteus software, for that purpose, I used 4052 component as a multiplexer (two of them actually, since one such component consists of two 4 to 1 multiplexers) and 40175 as a set of D flip flops. However, when I create this circuit, this is the warning I get:

Unfortunately, I failed to determine where $$\V_{ee}\$$ pin is actually located and what is the problem with it, but this is what happens with simulation:

As you can see, some sets of switches don't have their state (not even undefined), yet on the other hand, some of them seem to work just fine. What could cause this problem? Any help appreciated!

• Can you show your component list? And are you using the free (trial) version, or the full version? – MCG Apr 10 at 7:55