Hi Jacob,
thanks for your respond. I tested it with the Device Tester an got this result:
Lansweeper DeviceTester 7.1.0.1
Scanning Lansweeper Service (on this machine)..
	Status: Running
	Version: 12.5.4.0
Pinging 192.168.115.99
	Ping ok.
	TTL: 254
Scanning TCP ports..
	Open ports:
		21 (FTP)
		22 (SSH)
		23 (Telnet)
		80 (HTTP)
		443 (HTTPS)
	Closed ports:
		25 (SMTP)
		8080 (HTTP)
		135 (EPMAP)
		139 (NetBIOS Session Service)
		8443 (HTTPS)
		445 (SMB)
		9100 (Jetdirect)
		16992 (Vpro HTTP)
		16993 (Vpro HTTPS)
Scanning MAC..
	70:49:A2:21:53:E1
Scanning DNS..
	XMG1915.fritz.box
Scanning netbios (UDP)..
	Could not scan netbios
Scanning FTP..
	220 XMG1915 FTP version 1.0 ready at Tue Aug 19 17:31:28 2025
Scanning SIP..
	Error: Socket exception TimedOut: Ein Verbindungsversuch ist fehlgeschlagen, da die Gegenstelle nach einer bestimmten Zeitspanne nicht richtig reagiert hat, oder die hergestellte Verbindung war fehlerhaft, da der verbundene Host nicht reagiert hat
Scanning HTTP..
	Url: Http://192.168.115.99
	Response Uri: http://192.168.115.99/login.html
	Transfer-Encoding: chunked
	X-Frame-Options: SAMEORIGIN
	X-Content-Type-Options: nosniff
	Cache-Control: no-cache
	Content-Type: text/html
	Date: Tue, 19 Aug 2025 17:31:31 GMT
	Expires: Thu, 26 Oct 1995 00:00:00 GMT
	Set-Cookie: C1=youshallnotpass; path=/; HttpOnly; SameSite=Strict
	Server: Allegro-Software-RomPager
	Title: Login
Scanning HTTPS..
	Url: Https://192.168.115.99
	Certificate issuer:
		CN=XMG1915 7049a22153e1
		CN=XMG1915 7049a22153e1
	Response Uri: https://192.168.115.99/login.html
	Transfer-Encoding: chunked
	X-Frame-Options: SAMEORIGIN
	X-Content-Type-Options: nosniff
	Cache-Control: no-cache
	Content-Type: text/html
	Date: Tue, 19 Aug 2025 17:31:34 GMT
	Expires: Thu, 26 Oct 1995 00:00:00 GMT
	Set-Cookie: C1=youshallnotpass; path=/; HttpOnly; SameSite=Strict
	Server: Allegro-Software-RomPager
	Title: Login
Scanning SSH..
	SSH server: SSH-2.0-OpenSSH_3.9p1
	Error: No password
Scanning SNMP..
	SNMP disabled or wrong community
Scanning VPRO RMCPPing..
	No reply to RMCP ping
Scanning DNS-SD..
	No reply to DNS-SD
Scanning UPNP..
	No reply to UPNP
Done.
I don't know what could be the problem, as it worked before.

 
 
 
 
 
SNMP Setting of the switch

 
 
 
 
 
What can I do?