SUSE Manager webUI error 404 after upgrade

After the upgrade to SUSE Manager 4.3, the following is reported when trying to open the webUI:

### HTTP Status 404 – not found

Type Status Report

Description

The origin server did not find a current representation for the target resource or is not willing to disclose that one exists.

Apache Tomcat/9.0.36 ###

In the postgresql logs the below entries can be seen:

[unknown] [unknown] [31036]LOG:  could not accept SSL connection: no suitable signature algorithm

Re-create the server certificate and replace the old one:

rhn-ssl-tool --gen-server --dir="/root/ssl-build" --set-country="COUNTRY" \
--set-state="STATE" --set-city="CITY" --set-org="ORGANIZATION" \
--set-org-unit="ORGANIZATION UNIT" --set-email="name@example.com" \
--set-hostname="susemanager.example.com" --set-cname="example.com"

mgr-ssl-cert-setup --root-ca-file=<Path_to_Root_CA_Certificate> \
--server-cert-file=<Server_Cert_File> --server-key-file=<Server_Key_File>

spacewalk-service stop
systemctl restart postgresql.service
spacewalk-service start

/usr/bin/rhn-ssl-dbstore --ca-cert=<Path_to_Root_CA_Certificate>

An old signature algorithm is used in the server certificate:

Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number:
            xxx
        Signature Algorithm: sha1WithRSAEncryption
        Issuer: ...

The "sha1WithRSAEncryption" certificate algorithm is old and declared as insecure. It was used as the default in the past, but this was changed a while ago.

Documentation related to certificates:

https://documentation.suse.com/suma/4.3/en/suse-manager/administration/ssl-certs-imported.html#_replace_certificates

https://documentation.suse.com/suma/4.3/en/suse-manager/administration/ssl-certs-selfsigned.html