I have experienced the same problem but the scripting error was
<ScriptErrorDetails>
<Message>Unable to get property 'getValue' of undefined or null reference</Message>
<Line>1</Line>
<URL>/_static/_common/scripts/PageLoader.js?ver=1473065639</URL>
<PageURL>/main.aspx?etc=2&extraqs=%3f_gridType%3d2%26etc%3d2%26id%3d%257b030D8855-E480-DD11-8A7A-0019B9BECE08%257d%26pagemode%3diframe%26preloadcache%3d1375372062830%26rskey%3d148988450&pagetype=entityrecord</PageURL>
<Function>executeAction(action)</Function>
<CallStack>
<Function>executeAction(action)</Function>
</CallStack>
</ScriptErrorDetails>
This happened after importing a solution. We first tried to
move the order of the scripts on the contact form, republished, didn't fix it
disabled the newest script on the contact form, from the new solution, republished, didn't fix it
removed the new script completely from the contact form, republished, didn't fix it
Resorted to removing the solution completely, fixed it.
The CRM environment
Using CRM Online version 5.0.9690.3417
IE10
has other customized scripts on the contact entity that existed before the new solution was added
The solution works for other fresh CRM environments using the same version and IE10
The issue seems to be related to scripting conflicts between the customized scripts and the solution's scripts
Other References to the scripting error
stackoverflow.com/.../grey-ribbon-on-account-form-in-ie-script5-access-is-denied-in-pageloader-js