An ActiveX control on this page is not safe.

[PaulHuffman]

Why do you suppose I'm getting this Web Browser message on most tools since last week when I try to fill in an argument: "An ActiveX control on this page is not safe. Your current security settings prohibit running unsafe controls on this page. As a result, this page might not display as intended." ? It seems to pop up on the first thing I click on in a tool. Then I close the error message and I'm able to continue.  I don't normally use Internet Explorer, but I tried changing the IE security settings to medium. http://forums.arcgis.com/threads/10446-arccatalog-v10-internet-explorer-script-error-on-page-run-act...  I don't see a script error message so I don't think these work arounds would be helpful: http://support.esri.com/en/knowledgebase/techarticles/detail/38099   http://support.esri.com/en/knowledgebase/techarticles/detail/33792 

I'm running ArcGIS Desktop 10.1, SP1, Windows 7, 64 bit.

[JeffReichman]

Did you ever get a response to this or figure out how to correct.

Jeff

[RebeccaStrauch__GISP]

Although there are quite a few threads re: ActiveX errors, this one had the least amount to read thru.  Other threads (which are valid for many situations) discuss regedit of Zones.  In my case, none of those solutions worked, and this error was starting to cause issues with my ArcGIS Server publishing and caching too.

So just to throw this out there...Internet Explorer (IE) 10 and/or 11 is the culprit.  I uninstalled back to IE9 and things are back to normal.

[PaulHuffman]

I am having trouble with this again now that I have upgraded to ArcGIS Desktop 10.5.  I must have had settings that were not preserved in the upgrade.  I don't remember how I solved this last time. Still running Windows 10 Pro.  I don't see a way to uninstall IE,  11 in my case.  It doesn't show up under "Add or Remove Programs" and isn't it intertwined with the Windows OS?  I have gone through all the IE internet security setting as explained in Problem: Issues with ActiveX controls when launching ArcMap , restarted ArcGIS, rebooted, still have the problem.

Update:  I did find a way to uninstall Internet Explorer 11 in Windows 10 by going to Windows Features.  How to Uninstall IE11 From Windows 10    Still have ActiveX warning messages all over Arc Tools.  Even with IE uninstalled, the system still has Edge installed, and there are still the same Internet Properties>Custom Level>Security Settings to deal with.