As for issue #4, those errors occur in the third-party service Javascript code (http://s1.webspellchecker.net/spellcheck3/lf/opt_b.js) and there's nothing we can do about that. As for issue #2 I just couldn't reproduce that issue (on a real IE7 browser).

ICEfaces 1.8 revision 44976/ component-showcase [facelets-enh]:

Issue 1) can no longer be reproduced.

Issue 2) is still reproducible: in IE11/IE8, must change the Toolbar Mode and the tabs alternatively for 2 or 3 times.

In IE10/IE9 other errors were immediately reproducible by changing Toolbar Mode to "Basic":
SCRIPT5007: Unable to get value of the property 'open': object is null or undefined
about:blank, line 1 character 1
SCRIPT16389: Unspecified error.
ieerror.js, line 66 character 1

In IE11, Check Spelling feature is not functional, as it fails to load any suggestions; also, after attempting to use Spell Check, the "About CKEditor" window opens up blank.
Not an issue in FF34, Chrome43, or other IE browsers.
Steps:

• open the Rich Text demo in IE11.
• type "teste" in the inputRichText component.
• enable SCAYT, then click "Check Spelling" -> the Spell Checker does not provide any suggesstions (it displays "loading...).
• click "Finish Checking" on the Spell Check poup window -> the window does not close, so click "Cancel" to close the window.
• change Toolbar MOde to "Basic", then click the "About CKEditor" icon -> the "About CKEditor" popup opens up blank.
  This window is also blank if changing back the Tollbar Mode to "Default".

r44987: fixes for errors on IE8/IE9/IE10 when switching to the basic toolbar; fix for spell checking dialog on IE11.

I still can't reproduce the issue on IE11, please provide specific, detailed steps to reproduce the issue. Also, let me know what machine you tested on.

The issue with the About CKEditor dialog is still present, but given that this doesn't affect functionality, it will be given lower priority.

r45063: added fallback method of destroying previous instance.

This commit should fix the issues when switching between toolbar modes and tabs.

r45077: committed fixes for error popups when using the spellchecking plug-in.

Indeed, those errors are very random, and it's not always possible to reproduce them. I noticed that these errors were more likely to happen when quickly clicking different buttons and menu options, without giving a good pause for all the operations to complete before clicking something else. They also seemed more likely to happen after clearing the browser's cache.

These commits try to fix those errors that we know about. There might still be other random error messages, but they don't affect the normal functioning of the editor. It could also be that these errors are seen on our test machines because they are slower. I couldn't reproduce these errors using IE11 in previous versions modes.

As for the last issue, the error occurs in the third-party website code, and we don't have any control over it.