UITabbar icon shown on simulator but disappear on Device

I saw another guy posted a similar and the solutions in the replies do not work for me.

I have a UITabbar with 4 items, all icons show on simulator. but when I run it on device, the third icon does not show up while others are shown correctly. It's complete the same code & resources for dev开发者_StackOverflow社区ice and simulator and I really cannot figure out what's wrong.

Has anyone met the same thing?

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Check case of the filenames. Simulator is not case sensitive, the target is.