Caution! Don’t do this in a productive environment!
Add a security police “None” to the OPC UA configuration file.
On Windows you can find the file here: “C:\Program Files\Siemens\Automation\WinCCUnified\bin\OpcUaServerRTIL.xml”
<SecurityProfileUris>
<SecurityProfile>
<ProfileUri>http://opcfoundation.org/UA/SecurityPolicy#None</ProfileUri>
<Enabled>true</Enabled>
</SecurityProfile>
...
</SecurityProfileUris>