The textures of some blocks don't always show up when using a resource pack. It could be just only one block type like dirt or something and that some dirt blocks would be textured others not. In my attachment the block happens to be obsidian.
Edit: I dont think this is a duplicate as unlike the other issues im having this only when using a resource pack and its happening when building in chunks that already have blocks in it not empty chunks
14w25b:
That's probably not caused by your resource pack or aren't you having this issue without a resource pack?
Else it is caused by a bug where some graphic cards are not rendering chuks 😉
MC-56917 MC-56897