Today I found that Adguard is suddenly blocking captchas on uploadable.ch with IE 11. I tested it on a Virtual Machine without Adguard and the captcha was visible. I tried using the "do not block for 30 seconds" feature but it had no effect. I never had any problems before viewing captchas on this site with Adguard running. Here are screenshots: With Adguard: Without Adguard:
Works my end in Chronium and IE. Had to upload my own file to test and here is the link: http://www.uploadable.ch/file/uxMR76qzQmeQ/landscape_wallpaper_by_nickchoubg-d4yaep3.png but as you can see IE 11 and captcha with adguard running.
Could you please disable "Ad Blocker' in Adguard (but leave Browsing Security enabled) and clear browser cache? Also do you use Parental Control in Adguard?