Problem in my yahoo messanger?

In yahoo messenger when i send an im i cant see it. i mean i write the text and after i send it nothing happens. also i cant see the ims my conversational partner sends me, but i can hear the alert and see the message pop up in the down-right corner of my screen. i have reinstalled it several times but it's still the same. wtf do i do now? i scanned my computer with avira and malwarebytes anti malware. both programs are up to date and they dont pick up anything. please help m