Random Blocks are being deleted from my world.

Hola

Your game is modified. You need to be able reproduced the problem without any mods.

i dont think optifine has anyhting to do wether or not my blocks stay where they have been places long before i even installed optifine,

That looks like it might have burned down.

Probably a lightning burned it down.

Thank you for your report!
However, this issue is Invalid.

Your game, launcher or server is modified.
If you can reproduce the issue in a vanilla environment, please recreate the issue.

• Any non-standard client/server/launcher build needs to be taken up with the appropriate team, not Mojang.

• Any plugin issues need to be addressed to the creator of the plugin or resource pack.

• If you have problems on large servers, such as The Hive and Hypixel, please contact them first as they run modified server software.

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Wow well i hadn't even thought about the fact that lightning could strike. I could have sworn that it was in a biome where lightning couldnt strike or something