The document uses the font Univers 55, which is not available.
It gives me the option to use a replacement, so I do that, and all the hole call-out dimensions are broken or show the <DIM> codes in the drawing itself. How and why is this happening upon initial installation of the software?
Did you got the drawing from someone else? If yes then possibly he/she is using font Univers 55 and you get the error. So you can either request him/her to send you the font OR you can download and install.
I do not have font Univers 55 on my machine and that doesn't break down SW.