Can't make screenshot in minecraft with F2.
I have error while taking screenshot. It's caused by polish non-ascii character "ł" in path to file. Changing folder to that without polish characters is walkaround for the problem. Default minecraft folder has polish character, so it should be fixed without looking for walkarounds. Checked with "ł" and "ę". Both causes problem, so assuming that all polish characters like: żółćęśąźń will cause problem too.
17:33:37 net.minecraft.server.MinecraftServer Can't keep up! Did the system time change, or is the server overloaded? Running 6773ms behind, skipping 135 tick(s)
17:33:48 bxc Couldn't save screenshot
java.io.IOException: Could not write image to the PNG file "C:\Users\Michał\AppData\Roaming\.minecraft\screenshots\2018-02-10_17.33.48.png": Corrupt JPEG
at csp.a(SourceFile:306)
at bxc.a(SourceFile:45)
at bxc.a(SourceFile:30)
at bwu.a(SourceFile:256)
at bwu$$Lambda$290/1367900185.invoke(Unknown Source)
at org.lwjgl.glfw.GLFWKeyCallbackI.callback(GLFWKeyCallbackI.java:23)
at org.lwjgl.system.JNI.invokeV(Native Method)
at org.lwjgl.glfw.GLFW.glfwPollEvents(GLFW.java:2520)
at bxi.a(SourceFile:282)
at bwx.b(SourceFile:849)
at bwx.a(SourceFile:383)
at net.minecraft.client.main.Main.main(SourceFile:141)
17:33:48 bya [CHAT] Couldn't save screenshot: Could not write image to the PNG file "C:\Users\Michał\AppData\Roaming\.minecraft\screenshots\2018-02-10_17.33.48.png": Corrupt JPEG
Can you try under another user or with a .minecraft location outside of "C:\Users\Michał\"?