I keep getting a screen full of this when I try watching youtube on my macbook pro

"� ��P��}�z�8����t��dm��)��%y�e[^���O%B�)��d����9��\� ��<�<ɉ@�Hٖ�e��]).X�@ď@���r�tvu\!��o��/���B� �jV!�;V�l��}�PE�T��W�ii=gcn�Xd��������>rR��Ռ6{� ^���O���F��Lc^WT_ fϩC ���K�KK.���أO�j�y) {�wV�? ��f�w��t��A���8t�s�M�3x9�y���� ��u�~�h�����I��ն� ���p����r�cr���h��D?-��Z&�K���kk���/�^�����-/g� k�|.� ?�|:?��t�eW1ev%�.��9�//���4{�N�f�!�Aa�L~)�� B�U���R�I i�Fs.4[kh���j�� �SϢ5T`/0�K��je��P�Z��x ��f[�1��j���(�� ��)��r������k�>e��c�����Ɇ����f��0�v�;�Z���_�x� �)mz���_�%OO��'M�iv�Q�~GF�d͎ev���?H5m�s$����I� tӴ��r���ڀ)R]��Z-��*FS�)�\�]�� )��=Ӱi �N���@k+ص,50�͢�o@9��� �oQjH&�#�"

Any ideas on how to fix that? My computer is updated, and it only happens when I actually click on a video to watch.