Doesn't work Ubuntu

[killerdevildog11]

fl2000_drm$ make
make CHECK="/usr/bin/sparse" -C /lib/modules/5.11.0-36-generic/build M=/home/killer/Documents/00002_GIT/fl2000_drm modules
make[1]: Entering directory '/usr/src/linux-headers-5.11.0-36-generic'

ERROR: Kernel configuration is invalid.
include/generated/autoconf.h or include/config/auto.conf are missing.
Run 'make oldconfig && make prepare' on kernel src to fix it.

make[1]: *** [Makefile:745: include/config/auto.conf] Error 1
make[1]: Leaving directory '/usr/src/linux-headers-5.11.0-36-generic'
make: *** [Makefile:21: modules] Error 2

then go to source it does this

:/usr/src/linux-hwe-5.11-headers-5.11.0-36$ sudo make oldconfig && make prepare
[sudo] password for killer:
HOSTCC scripts/basic/fixdep
HOSTCC scripts/kconfig/conf.o
HOSTCC scripts/kconfig/confdata.o
HOSTCC scripts/kconfig/expr.o
LEX scripts/kconfig/lexer.lex.c
flex: -Cf/-CF and %option yylineno are incompatible
make[1]: *** [scripts/Makefile.host:9: scripts/kconfig/lexer.lex.c] Error 1
make: *** [Makefile:629: oldconfig] Error 2

[ping-mee]

I have the same Problem :(

[HRIDOY-BUZZ]

Experiencing the Same issue in Kernel 5.13
Anyone solved it yet?

[larrasket]

Same