There is a small folder inside the minecraft/bin
folder called natives
. This folder contains files that have platform-specific code. When you copied over your install, you copied over the Windows-native files in this folder. As a result, the game fails to run.
You can fix this by replacing the contents of that folder with the correct files from a valid 1.4.6 installation that was done on a Mac.
I'm not entirely certain how you can do that, but the files from a 1.4.7 install may work if in fact Mojang have not changed very much except for some classes in the main jar file. Archive your modded install somewhere else, install MC 1.4.7 fresh, and save the natives
folder it generates somewhere convenient. Wipe the rest and put your modded install back in place, remove its Windows-based natives
folder, and drop in your new one. See if it runs.
If using a 1.4.7 natives
folder doesn't work though, one way to try would be to use Minecraft Nostalgia, which can downgrade the latest version of Minecraft to an arbitrary previous version. (I've used it for downgrading to 1.2.5 for modding purposes, but I haven't done it on a Mac. It appears to support Win/Mac/Linux though.)
You would safely archive your modded install, wipe it from the minecraft/
folder, then run the vanilla launcher to get 1.4.7. Close it out, then run Minecraft Nostalgia, choosing 1.4.6 from the list. Once it's done the conversion, grab the minecraft/bin/natives
folder for later. Wipe the rest, put your modded install in, and delete the minecraft/bin/natives
folder that came from Windows. Finally, drop in your natives/
folder gleaned from MC Nostalgia, cross your fingers, and launch!
Again, I've never had to do this, but it should work.
I just checked the launcher and this is how it does it:
It loads .minecraft\launcher_profiles.json and looks at "selectedProfile":
{
"profiles": {
"1.6.4": {
"name": "1.6.4",
"lastVersionId": "1.6.4",
"playerUUID": "---"
},
"default": {
"name": "default",
"playerUUID": "---",
"launcherVisibilityOnGameClose": "close launcher when game starts"
}
},
"selectedProfile": "default",
"clientToken": "---",
}
Then it looks at the selected profile's lastVersionId and uses that version (e.g. 1.6.4). If there is no such attribute (as in the above example), it lists all versions from the versions folder, reads the json files and chooses the one with latest "releaseTime" attribute. It also filters the versions by "type" == "release" attribute (this filtering actually depends on the profile settings, but by default only "release" versions are considered).
Best Answer
The "pumpkinblur.png" file is the image that overlays your HUD (in first person view) when you wear a pumpkin on your head.
In resource packs, it's not uncommon to replace this with another image, especially when the view is so restrictive. I.e.:
So basically, this image is only relevant when you have a (sheared?) pumpkin on your head.