I did all thats mentioned in prev posts, like clearing cache, deleting cookies, re-setting browser to factory mode, and opening browser in safe mode, was still, not able to view certain charts, either in firefox or chrome. So I installed Tor browser, as a temp. measure. I can view all charts now.
During weekend will check to find out, how to rectify this issue for firefox and chrome.
Google for Tor browser, check the if's and but's if it suits you, install it, there are tutorials on how to use it.
Thanks and regards.