LinLog

I ran into an interesting issue today while testing out an ownCloud installation on a new company laptop running Windows 10.  When trying to open the site in IE11, JavaScript would just die.  And I mean die hard.  Basically nothing on the page worked at all.  Yet it was perfectly fine in Edge, Firefox, and Chrome.

The problem was an "Access denied" message on a seemingly innocuous line of code.  It was a test for local storage support.  The exact line was:

if (typeof localStorage !== "undefined" && localStorage !== null) {

Not much that could go wrong with that line, right?  Wrong!  When I double-checked in the developer console and it turns out that typeof localStorage was returning "unknown".  So the first part of that condition was actually true.  And attempting to actually use localStorage in any way resulted in an "Access denied" error.

A little Googling turned up this post on StackOverflow.  It turns out this can be caused by an obscure error in file security on your user profile.  Who knew?  The problem was easily fixed by opening up cmd.exe and running the command:
icacls %userprofile%\Appdata\LocalLow /t /setintegritylevel (OI)(CI)L