Arduino IDE not even compiling Empty sketch

i have been working on arduino uno and NodeMCU but recently i am facing an issue, where the IDE doesnt even compile a single sketch, not even and empty new sketch with no lib files included…

so fed up with this i wanna work like before again…

plzz help…

this is the sketch

void setup() {
  // put your setup code here, to run once:

}

void loop() {
  // put your main code here, to run repeatedly:

}

this is the error

In file included from C:\Users\....\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\2.5.2\cores\esp8266/Arduino.h:27:0,

                 from sketch\MQTTcloud_test.ino.cpp:1:

C:\Users\....\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\2.5.2/tools/sdk/libc/xtensa-lx106-elf/include/stdlib.h:16:20: fatal error: stddef.h: No such file or directory

 #include <stddef.h>

                    ^

compilation terminated.

exit status 1
Error compiling for board NodeMCU 1.0 (ESP-12E Module).

hey actually got it i just went to AppData\Local\ and deleted the " Arduino 15 " folder and everything is back to normal, this is maybe due to messing up the lib folder/files

That's great you got it fixed! I was just posting instructions suggesting you do exactly that, but your reply came in first. Thanks for taking the time to post an update. Enjoy!
Per

thanks, I had to just clear out the libraries cuz I downloaded a lot of them, so they were unnecessary.

Job Done!
Thanks for responding though!!