about 5 minutes after i open minecraft, the world that i'm using starts to flash an many blocks dissapear. i have to minimize the game, but when i come back, i put 10 blocks and start to flash again.

Thank you for your report!
However, this issue has been temporarily closed as Awaiting Response.

We do not have enough information to find the cause of this issue.
Please force a crash by pressing F3 + C for 10 seconds while in-game and attach the crash report ([minecraft/crash-reports/crash-<DATE>-client.txt|http://hopper.minecraft.net/help/finding-minecraft-data-folder]) here.

Once attached, the report will be reopened automatically.

Quick Links:
📓 Issue Guidelines – 💬 Community Support – 📧 Customer Support – 📖 Game Wiki