If you already have a corrupt version and cannot find a clean one, here is a 5-minute workflow to fix the most common issues:

The PDF was fixed, meaning that it had been carefully crafted and refined over the years to convey the precise principles and proportions that governed the design of St. Sophia's Cathedral. Emma was captivated by the precision and attention to detail that had gone into creating the document. She spent hours studying the geometric patterns, proportions, and symmetries that underpinned the cathedral's design.

If columns and windows are the words, the way they are combined constitutes the syntax. Architectural grammar governs how these parts relate to one another to create a unified whole.

A single fixed plate from The Grammar of Architecture (for example, Plate VI, "The Nature of Gothic") explains the logic behind 70% of pre-1900 Western buildings. Without that visual clarity, you are learning architecture with your ears covered.