Red circle appears when using tools such as "Linear Dimension"

[retrac116]

I just recently upgraded from the 2007 version of Autocad to the 2013 Mac version. When i try to use tools such as the Linear Dimension tool a red node (A circle with a cross inside) appears and locks on too specific intersections which prevents me from doing what I need. Any help would be appriciated. My pointer is nowhere close to where the "Red Node" is locking.

I also am wondering about the text. After I get the dimension right D=........ comes up. If there is a way to get rid of this it would be greatly appriciated.

I have attached a file showing exactly what is happening.

Thanks in advane for all of the help. 

[maxim_k · Accepted solution]

Welcome to Autodesk Forums!
Hi,

You are using wrong dimension tool: constrained dimension from parametric feature instead of ordinary dimension.
Try to use menu Dimension-> Linear, or use dimension tool from Annotate tab of Toolsets palette, or in command prompt type DIMLINEAR, DIMALIGNED, etc.

Maxim