There could be multiple reasons why this error popped up on screen.
If you took a poll of why this error was elicited, you will find that the main reason is the popup blocker. This leads us to the question of why the popup blocker exists.
It was created as an attempt to stop advertisement windows and random popup windows that are incorporated in most websites. Sometimes, these popup blockers also inhibit process flow by blocking the Java scripts from executing.
t is best if you manually configure your popup blocker to allow Java scripts if you want to avoid seeing this error every time you visit a website loaded with Java. In some popup blockers, there may not be a set of preferences which allow this feature. Therefore, you will have to choose your popup shield very carefully after reading reviews and checking to see if it allows Java scripts or not.
The second main reason can be attributed to use of proxy websites to browse a web page. We normally use proxy websites to mask our IP addresses and browse banned sites or to even be anonymous. But this block most of the web scripts running on the page. Most proxy websites are designed to be lightweight and use the minimum features to open web pages.
While some websites are effective at blocking popup windows, they stop the execution of Java scripts also. Therefore, it is wiser to avoid the use of proxies or use a proxy website that allows you to configure your preferences to allow scripts.