PdfTeX error: pdflatex (file ecbx0800): Font ecbx0800 at 600 not found
You shouldn't be getting that error message but adding
\usepackage{lmodern}
will switch to a more or less compatible font set that probably avoids the errors you are getting.
You asked in comments for details of what exactly this changes:
The original extension of the TeX computer modern fonts to 8bit encodings were the "EC" fonts, and these are the latex default fonts if you use
\usepackage[T1]{fontenc}
Like computer modern, these were originally metafont fonts used as bitmap fonts in any generated pdf (and so look horrible and jagged in acrobat). There are however scalable (type 1) versions of these, using the same metrics..
So there are a couple of things wrong with your installation but a bit hard to debug at a distance.
If you specify (in your font map configuration) that you want the original metafont versions, then metafont is supposed to start and generate the font, not stop with a font not found error. But..
The configuration is supposed to say that these fonts are available in type1 form already, and so not try to generate them with metafont by default.
Perhaps someone who has used miktex could point you to the right configuration options there, but meanwhile..
latin modern is a newer far more extensive interpretation of the computer modern design, available in type1 (for pdftex) but also covering more of teh unicode range in open type format (for xetex luatex or any other modern non-tex system that wants that look) It is the default font if you use fontspec with xelatex or lualatex. So basically it looks the same as computer modern/ec but it is in fact a completely different font set, and there may be minor differences in letters and spacing (but the metrics for spacing are I think the same in the T1 encoding range)
So depending on your time and priorities you could track down what's wrong with your ec configuration, or you could just use latin modern and forget about it....
I was experiencing this very problem with the package dgruyter.sty.
The problem went away after I installed the package cm-super (I'm in Linux)