Q: safari web links do not respond and newly opened tabs disappear ?

When I try to click and write a new web address it does not respond and I can't write anything into it and so I have to open a new tab which occasionally disappears. Also when I full screen safari it closes down and a window pops up saying that it closed down unexpectedly and if it stay enlarged then it closes down when I click in the bow where you type the web address. If anyone can help me resolve the problem I will appreciate it thanks.