TEAMVIEWER 12 BLOCKED )DOES NOT PRESENT MY ID NOR CAN I TYPE REMOTE ID

HI,
I HAD TO REMOVED VERSION 11 (WHICH WORKED OK) AND UPGRADE TO VER. 12 BUT THIS NEWER VERSIONS DOES NOT CONNECT.
VERSION 12 DOES NOT PRESENT MY ID AND PASSWORD NOT DOES IT LET ME TO TYPE A REMOTE ID.
I SEARCHED GOOGLE AND FOUND MANY COMPLAINTS - SOME WERE SOLVED BY DECLARING TCP/UDP Ports IN THE FIREWALL.
I AM NOT STRONG IN COMPUTER CUSTOMIZATION AND AM AFRAID TO RUIN SOMETHING.
WHY IS VERSION 11 WORKING AND VERSION 12 NOT ?
(IF I WILL UNISTALL VER. 12 AND INSTALL VER. 11 (I HAVE AN INSTALLATION FILE) IT WILL WORK OK BUT MOST USERS HAVE VER. 12 AND VER. 11 REFUSES TO WORK OPPOSITE VER. 12.
IF THERE IS A WAY TO FORCE VER. 11 TO WOK WITH VER. 12 THIS COULD BE A GOOD WORKAROUND FOR ME.
AWAITING YOUR SUGGESTIONS.
THANKS,
MICHAEL