Problem with HA out of sysyem resorce

Hello, every few days I have this problem with my HA (latest version on RPI 4 and SSD drive). Do you know, what happened?

Blockquote [email protected] - Home Assistant
   Loaded: loaded (/etc/systemd/system/[email protected]; enabled; vendor preset: enabled)
   Active: failed (Result: signal) since Tue 2020-12-22 11:41:06 CET; 12min ago
 Main PID: 16041 (code=killed, signal=KILL)

Dec 22 08:15:19 server hass[16041]:   File "/usr/local/lib/python3.9/asyncio/selector_events.py", line 164, in _accept_connection
Dec 22 08:15:19 server hass[16041]:   File "/usr/local/lib/python3.9/socket.py", line 293, in accept
Dec 22 08:15:19 server hass[16041]: OSError: [Errno 24] Too many open files
Dec 22 08:15:19 server hass[16041]: 2020-12-22 08:03:50 ERROR (MainThread) [homeassistant] Error doing job: socket.accept() out of system resource
Dec 22 08:15:19 server hass[16041]: Traceback (most recent call last):
Dec 22 08:15:19 server hass[16041]:   File "/usr/local/lib/python3.9/asyncio/selector_events.py", line 164, in _accept_connection
Dec 22 08:15:19 server hass[16041]:   File "/usr/local/lib/python3.9/socket.py", line 293, in accept
Dec 22 08:15:19 server hass[16041]: OSError: [Errno 24] Too many open files
Dec 22 11:41:06 server systemd[1]: [email protected]: Main process exited, code=killed, status=9/KILL
Dec 22 11:41:06 server systemd[1]: [email protected]: Failed with result 'signal'.