Don't know if you're still around, but I'm noticing these in the log:

Script @__factoriohd_base__/data-final-fixes.lua:257: [ERROR]: Image @ __factoriohd_base__/data/base/graphics/entity/rocket-silo/hr-08-rocket-silo-arms-back.png is wider / taller than 8192 px (maximum)! It can't be loaded into the game!
Script @__factoriohd_base__/data-final-fixes.lua:257: [ERROR]: Image @ __factoriohd_base__/data/base/graphics/entity/rocket-silo/hr-08-rocket-silo-arms-right.png is wider / taller than 8192 px (maximum)! It can't be loaded into the game!

Ok, realizing now these log messages were from your mod, not the game itself, but...

It should be noted that these are being reported with your default settings (upscale = 2). Further, these are the actual file sizes:
hr-08-rocket-silo-arms-back.png - 8192 x 300
hr-08-rocket-silo-arms-right.png - 11648 x 376

So, even with an upscale of 1, your mod would still refuse to load them (as it does a >= check, and one is a little less than 1.5 times too big anyway).

agreed