Every time we update the NLVM website like we did a few weeks ago we receive email from people that are no longer able to access the applets. Often times the causes are somewhat mysterious. Some of the problems are caused by proxy and browser caching; some of the updated files arrive at peoples’ browsers and others do not. After a few days the problems seem to work themselves out.
Other times problems occur because we broke something and we didn’t catch it in our testing. This is aggravated by browser incompatibilities. Because old hardware and software tend to hang around schools longer than other places, strange things show up. Right now I’m trying to track down some of those types of issues.
A few years ago when I was more actively developing the NLVM I used to keep old machines around so I could test old browsers. One of the reasons multiple machines were needed was that I couldn’t find an easy way to run multiple versions of Internet Explorer on the same machine. Yesterday I googled to see if there is anything new out there to help with this issue. I was pleasantly surprised to find a utility by tredosoft that allows you to install multiple versions of IE on your PC. Thanks tredosoft! Unfortunately after installing the multiple browsers, I’m still not able to see the reported problem even when running on the same browser.