Textures sometimes disappear.

[Seth Hetu]

Textures either disappear or objects fail to draw them. In some cases, this leads to big issues (invisible turrets that can't be destroyed) and in others it is just annoying (lifts that work, but are invisible).

One of the first places this occurs is Sector 5(?) in the big outdoor area; there's a turret on the top-right that is invisible every time.

This glitch seems to always occur to the same objects, but it does not always trigger.

[Seth Hetu]

This bug by Ezra G Melman may be related:

6) When restarting a level sometimes, the items (nano, health, etc). that you have picked up before don’t appear the second time.