Local mac installation problem

There probably is a simple solution for this, I just can’t find it!

I did a local installation of WP on my mac, just to play around with it. Once installed, posted a test post. Works fine.. until I try to insert a link: the insert link window pops up but the wp-window goes gray and non-responsive. Only thing I can do is to close the browser (Safari) tab.

Full disclosure: I am new to mac, just love almost everything mac, since it’s user-friendliness.. also new to wp.

Solutions, anyone?

Regards,
Juha