Failed to verify authentication

There is an error in the game output when starting.

Failed to verify authentication com.mojang.authlib.exceptions.InvalidCredentialsException: Status: 401 at com.mojang.authlib.exceptions.MinecraftClientHttpException.toAuthenticationException(MinecraftClientHttpException.java:56) at com.mojang.authlib.yggdrasil.YggdrasilSocialInteractionsService.checkPrivileges(YggdrasilSocialInteractionsService.java:112) at com.mojang.authlib.yggdrasil.YggdrasilSocialInteractionsService.<init>(YggdrasilSocialInteractionsService.java:42) at com.mojang.authlib.yggdrasil.YggdrasilAuthenticationService.createSocialInteractionsService(YggdrasilAuthenticationService.java:151) at dvp.a(SourceFile:670) at dvp.<init>(SourceFile:429) at net.minecraft.client.main.Main.main(SourceFile:179) Caused by: MinecraftClientHttpException[type=HTTP_ERROR, status=401, response=null] at com.mojang.authlib.minecraft.client.MinecraftClient.readInputStream(MinecraftClient.java:77) at com.mojang.authlib.minecraft.client.MinecraftClient.get(MinecraftClient.java:47) at com.mojang.authlib.yggdrasil.YggdrasilSocialInteractionsService.checkPrivileges(YggdrasilSocialInteractionsService.java:104) ... 5 more

 

I tried many ways to try fixing this but it doesn't work.  Can someone please help?

PS: I am using Minecraft DEMO, and it says that I have an invalid session ID.