DxDesigner Design Rule Check Errors
As a first port of call I would try loading the help documentation in DxDesigner.? There is actually a surprising amount of information which has helpful search functionality. 

In any case, hopefully the following will help:


DRC-106 is basically you have more than one pin of type "output" connected to a net (e.g. two logic gate outputs) which is usually indicative of either a bad connection, or incorrect pin type in one or other of the symbols.
DRC-121 indicates that you have a hierarchy symbol (e.g. "hier-in" or "hier-out", etc.) symbol attached to a net in your schematic, but you are not using it for anything. As such that symbol is redundant.


Not sure about DRC-001.