[PROBLEM] Error 500 after new istallation

[traillight]

Hi, i just installed the 8.3.2 version from image.
Everything words after boot, but after some time ideling i get an internal server error 500.
Also i cant get a connection with ssh, i have to reboot the rpi. 
then everything starts from new.

can someone help me fix this problem?

system:
rpi 3b
16gb sd card
only moode is running