I was looking at some older IconPackages and many were missing icons.

The two best ways I found for fixing them is drag and drop and using the "Similar Icon" option.

For both, the way to start is to apply the icon package and then select "Customize" from the left panel.

To drag and drop, open Windows Explorer and navigate to C:\Users\Public\Documents\Stardock\IconPackager and then to the package you want to get the icons from

Then just drag and drop from the Explorer Window to the icon in IconPackager

For the other method, double click on the icon you want to change and then select "Similar Icons" in the upper left.

Pick one you like!

For me it was just in Cortana that this happened.

IconPackager is working well here with no problems.  Love the IconPackager title and graphics too. Thanks, Neil! 

Could you provide a screenshot please.

This does not sound normal.  If there is another icon on top of the others then could it be the shortcut arrow that many iconpacks replace?

I have none, unfortunately. I uninstalled the software. Tried to repeat it now, but now it is working next time, i'll do the screenshot and post it here. Sorry for any inconveniance.

well, I'm unhappy to report that IP killed some of my icons already (newsleecher and VMware) showing only default icons

I made a clean install Win 10 on a win 8.1 HP almost a year ago

I have Object desktop so I only installed Start 10, windowblinds,

deskscapes, WinFX, cursorFX plus,  tiles, fences...

I installed yesterday IP-10 my icons on start menu disappeared

a default blank icon showed but they open the apps then yesterday the apps didn't click open at all

then the start menu didn't open. I uninstalled IP 10 and follow this Microsoft steps

Method 3: Troubleshooting Store.

Step 1: Reset Windows Store

1. Press Windows + R, to open run prompt.
2. Type wsreset and press enter

This command will reset the windows store cache.

Step 2: Re-Register Store App.     <-- it restores Start windows 10 Menu

1. Press Windows + X, Click on Command prompt (Admin).
2. Copy the following command and paste in command prompt and press enter.

powershell -ExecutionPolicy Unrestricted Add-AppxPackage -DisableDevelopmentMode -Register $Env:SystemRoot\WinStore\AppxManifest.XML

Method 4: Run the following command in PowerShell.

1. Press Windows + X, Click on Command prompt (Admin).
2. Type powershell in command prompt and press enter.
3. Copy the following command and paste in command prompt and press enter.

Get-AppXPackage | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register "$($_.InstallLocation)\AppXManifest.xml"}

The store apps are restored but not my the other icons such as mozilla, all of the stardock icons. They do open on click

but a notification of "object not found" flashes right before. So I went to a Restore point from last week and restored my laptop...

'but I had no luck.... the icons are still the same--BLank.

I love Icon Packager but I am afraid of installing it back again. Any help would be appreciated.

What else is happening?

same as starchefmonique, had to restore to get icons back and start menu working.  NOT gonna install again for now...

Since re-applying the icon pack and several shut downs later the icons remain. Not going back to default icons. I are a happy camper now. Kudos to the devs, you guys rock!! 

I get shortcut overlays on some sets, this odd look on others.

I have shortcut overlays turned off (hidden) in WinFX.

Check your iconpack and see what it has set for shortcut overlays.  Also did you have IconPackager v5.x ever installed on this OS?

The feature in WindowFX only applies to icons on the Desktop...