This bug happened to me 10 times, it happened to me twice this morning and luckily none of my worlds got corrupted but hopefully it doesn't corrupt any of my worlds, also after I fullscreen it said "Saving World" and then it crashed!

I was going to start the game when I fullscreen this happened:

[Render thread/FATAL]: Unreported exception thrown!

[Render thread/FATAL]: Unreported exception thrown! java.lang.RuntimeException: GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT at ded.b(SourceFile:172) ~[1.16.3.jar:?] at ded.b(SourceFile:149) ~[1.16.3.jar:?] at ded.d(SourceFile:65) ~[1.16.3.jar:?] at ded.a(SourceFile:54) ~[1.16.3.jar:?] at eab.a(SourceFile:316) ~[1.16.3.jar:?] at dzw.a(SourceFile:800) ~[1.16.3.jar:?] at dzr.a(SourceFile:301) ~[1.16.3.jar:?] at djw.a(SourceFile:1131) ~[1.16.3.jar:?] at dew.b(SourceFile:268) ~[1.16.3.jar:?] at dew$$Lambda$2354/2035430543.invoke(Unknown Source) ~[?:?] at org.lwjgl.glfw.GLFWFramebufferSizeCallbackI.callback(GLFWFramebufferSizeCallbackI.java:37) ~[lwjgl-glfw-3.2.2.jar:build 10] at org.lwjgl.system.JNI.invokeV(Native Method) ~[lwjgl-3.2.2.jar:build 10] at org.lwjgl.glfw.GLFW.glfwPollEvents(GLFW.java:3101) ~[lwjgl-glfw-3.2.2.jar:build 10] at com.mojang.blaze3d.systems.RenderSystem.flipFrame(SourceFile:109) ~[1.16.3.jar:?] at dew.e(SourceFile:308) ~[1.16.3.jar:?] at djw.e(SourceFile:1043) ~[1.16.3.jar:?] at djw.e(SourceFile:656) [1.16.3.jar:?] at net.minecraft.client.main.Main.main(SourceFile:215) [1.16.3.jar:?]