It may have gotten time that your iPad is just too out of date and the software that is in the browser that you are using may not be able to play the videos anymore or doesn’t support the codec that is needed to play the video. You can try resetting your iPad by pressing and holding the power button and the home button till you see the Apple Logo. If you see a slider “Slide to turn off” continue to hold the buttons and ignore the slider. Let the iPad continue to boot and release both buttons when you see the Apple Logo. Once the iPad boots back up, you can try again and see if this helps. However, if it doesn’t, then it is most likely time to replace the iPad with a newer updated model so you can run more up to date software as the iPad 2 cannot support any updated software.