Here are some examples:
Sculpt mode, some sculpt “brushes” do not work. On one of these sculpt bushes, the “add” and “subtract” buttons set the brush to do exactly opposite of their label - “add” actually subtracts, and “subtract” actually adds. This sculpt mode calamity only effects one of my projects, however, making it file specific.
Mirror flip function applied to one of my objects (Ctrl-M,X) produces an X-mirrored translation of my object, as it should, but it also rotates the object about 85 degrees, which it should NOT do. If it rotated my object exactly 90 degrees (or some interval of 90) I’d be happier because I could compensate for this error by counter-rotating it exactly -90. My best guess as to why this function adds the rotation is that my object is a modified primitive that I rotated about 85 degrees prior to doing the X-mirror function. My objection here is that none of the tutorials on the Mirroring function mention anything about this scenario, let alone what to do about it. I still don’t know what to do about it. The Mirroring function should mirror-translate the object as is, not as it once was.
Anyway, I compensated for this problem by copying the rotation angles from a non-mirrored version of the object, and negating the relevant angle values.
My next problem with that same mirrored object is that it cannot be boolean unioned with another object. When the boolean union modifier is applied to that object, the other object simply disappears. In fact, it does not matter which of the two objects I apply the modifier to. The other object always disappears. Any two other objects can be boolean unioned. But not my problem object.
I had an X-symmetrical humaniod object that had somehow gotten translated off the global origin, slightly in the -X direction. I wanted to translate it back to center it on the global origin. My attempt to do this produced laughable results. I put the 3D Cursor on the global origin (Shift-C) and put the humanoid object origin to the 3D Cursor (Shift-Ctrl-Alt-C, Origin to 3d Cursor), then I put the humaniod geometry centered around its object (Shift-Ctrl-Alt-C, Geometry to Origin). The result: humaniod object is grossly distorted – arms stretched out toward the sky 3 or 4 times their normal length, abdomen and legs looking like they’ve been in some horrible car accident.
Maybe this problem comes from the fact that the humanoid object is an import from MakeHuman, and therefore has the Y and Z axes labeling convention swapped with respect to the Blender global axes labeling. I don’t know. How am I supposed to know what the problem is, or what to do about it?
Anyway, it is this constant wall of problems that make me wonder whether my installation of Blender is working right.