ok then assuming the credentials in there are right, can you try and check on mysql if the db exists and the user guacadmin is in there?
If that’s ok, you could confirm whether guacamole is actually trying to login from either LDAP or mysql, check some logs
to enable LDAP logging
ldapmodify -Y EXTERNAL <<EOF
To disable it:
To enable tomcat logging:
put this inside
and check if the logs have anything to say as you login
tail -f /var/log/tomcat/catalina.out
tail -f /var/log/slapd
Also, does the folder /usr/share/tomcat/.guacamole/extensions/ contain guacamole-auth-jdbc-mysql.jar and guacamole-auth-ldap.jar?
Is there a file like mysql-connector-java-5.x.yz-bin.jar inside /usr/share/tomcat/.guacamole/lib/?
(paths may differ depending on how you installed it)