Loading a previously saved world results in no blocks except for mobs, pistons, redstone, and chests being generated.
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If you have any resource packs in the world (or possibly in Global Resources), they may need to be updated to work with 1.8.0. Try removing any resource packs and see if that temporarily fixes the problem.
Otherwise, it's possible that your 1.8.0 update had a problem during installation. Try backing up (exporting) your worlds, then uninstalling and reinstalling Minecraft.
Please let us know the results.
If you have any resource packs in the world (or possibly in Global Resources), they may need to be updated to work with 1.8.0. Try removing any resource packs and see if that temporarily fixes the problem.
Otherwise, it's possible that your 1.8.0 update had a problem during installation. Try backing up (exporting) your worlds, then uninstalling and reinstalling Minecraft.
Please let us know the results.
No resource packs in the worlds or in global. Copying the worlds from the save location to another folder and reinstalling does fix the issue.
No resource packs in the worlds or in global. Copying the worlds from the save location to another folder and reinstalling does fix the issue.
Since the problem seems to have gone away, I'm going to assume there was no bug, just an error during installation. If there is still an issue here, feel free to leave a comment.