Descriptive Problem Summary:
We moved our SS13 fork over to 64x64 sprites (up from 32x32) by upscaling all the DMI files with automated scripts (using the nearest neighbor algorithm).

Well it turns out this breaks the mapper in some way or another, like half the sprites are failing to render and then when they do render it's sometimes broken.

It appears that only certain icons are failing to load, if an icon appears somewhere it works everywhere, else not. It's consistent between restarting DM whether or not an icon actually works.

Screenshot BEFORE we moved to 64x64:



AFTER



Rendering issues on the before screenshot (like areas being invisible) are due to id:2127158

Numbered Steps to Reproduce Problem:
Download https://github.com/d3athrow/vgstation13/archive/ Bleeding-Edge.zip and then open maps/tgstation.dmm

I wish I was able to provide a better test case but sadly I can't reproduce this in a smaller scenario.

Does the problem occur:
Every time? Or how often? Every time.
In other games? N/A
In other user accounts? Yes
On other computers? Yes

When does the problem NOT occur?
When we don't move to 64x sprites.

Did the problem NOT occur in any earlier versions? If so, what was the last version that worked?
Untested

Workarounds:
Write your own mapper.