Pioneer DDJ-SZ problem with Serato DJ - Master output level missing !

After upgrading Serato DJ software to version 1.8.2, there was something very strange happend (after few days of use without any problems) Master Level Output indicator is suddenly disappeared. Just like that....I tried several different versions of Serato DJ 1.7.9, 1.8.0, 1.8.1 and finally 1.9.0 without success. Problem is still here. ...Any idea ? The settings in the controller are factory default and firmware 1.20. Everything else works perfectly, all other channel level output indicators works normally also)