Hi Kat,
The first error appears to be an encoding error in the page itself, most likely a Java applet. Clicking yes will simply tell your browser to continue loading all other such applets on the page. Clicking no will abort such, and certain parts of the page may not load or be properly visible. Clicking yes in not likely to do any harm. Nothing much to worry about. Disabling Java script in Internet Explorer will probably remedy this, but will likely cause certain difficulties with some webpages.
The second error appears to be a bad browser extension used to open Adobe Acrobat (.pdf) files. The easist way to remedy this would be to remove the bad application (browser extension), though you may then be unable to view webpages or web content in this format. If it is causing Internet Explorer to crash and you are unsure as to how to remove it, you could always -- at least for the time being -- go under Tools>Internet Options>Advanced and uncheck "Enable Third Party Browser Extensions" and restart your computer.
I hope this is of some help. I know there are people here who perhaps can offer a better solution.
Take care.
