Long story, so I'm not going to go into all of it. The bottom line is that I recently had to uninstall and reinstall Nexus Ultimate. I have used this program for years at this point and have a large collection of images to use as icons, some ICO and some are PNG. Since I reinstalled the program today ICO files are still fine. However, every time I try a PNG file I get an error. "You don't have permission to open this file." This is ONLY happening with PNG files which are stored in the same folder as the ICO files. Several are images I made myself and was using right up to the point of uninstalling a couple days ago. I've checked my security settings for the folder I keep them in and for the individual files, everything is fine. Even running Nexus as administrator doesn't do anything. Anyone have any ideas?

Almost willing to bet that this is caused by Windows going overboard with security (what isn't these days? Sigh)

Can you open these PNGs in a standard app like MS Paint or Photos right now? Anyway:

1. Check if Windows has “blocked” the PNG files

Since you reinstalled, Windows might be treating these files as "downloaded from another computer" for security reasons.

Right‑click one of the PNGs > Properties.

If you see an “Unblock” button or checkbox at the bottom of the window, click it.

Windows sometimes flags image files this way, and when that happens, every program (including Nexus) is prevented from opening them.

2. Why ICO files still work

ICO files are treated as system‑safe.
PNG files are not — they can be flagged by:

Windows SmartScreen
Controlled Folder Access
AV ransomware protection
File‑origin metadata (“downloaded from the internet”)

So it’s normal for ICOs to work while PNGs fail.

Any other program I have will open PNG files. Paint, Gimp, Edge, Photos. They can all open and edit PNG files without any trouble. The only program that can't access them is Nexus. I checked the permissions for a couple of the specific images that Nexus couldn't open, they are not blocked in any way.

If Paint, GIMP, Photos, etc. can open the PNGs, then the files themselves are fine — this isn’t a permissions issue on the PNGs.

The screenshot you posted shows permissions for SYSTEM, which always has full control, so it doesn’t tell us anything about your user account or about what Windows allows Nexus to access.

Also, ICO files don’t go through the same security checks as PNG files — Windows treats ICOs as trusted system resources. So ICO working does not rule out Windows blocking Nexus from reading PNGs.

To narrow this down, I need three things:

1. What is the full path to the folder containing the PNGs?

2. What is Nexus’s current Data Folder? (Preferences → About tab → “Open Data Folder”)

3. How exactly did you reinstall Nexus? Did you get a UAC prompt when running the installer?

These three answers should tell us whether Windows is virtualizing the folder, blocking Nexus’s access token, or running Nexus under a different security context than before.

Also, have you already tried moving or copying the PNGs to a different folder? Can Nexus access them from the new folder?

So, I have tried moving the png file to my desktop and open it in Nexus from there. No go, same response. The location of the data folder is C:\ProgramData\WinStep. I don't know what a UAC prompt is, so I don't know if I got one.

However, I have discovered another problem. The command to empty the recycle bin doesn't work. When I right click on my recycle bin on the dock there's an option to empty the bin. I used to always use that, but now that I have reinstalled the program it doesn't work. I don't get an error message or anything, just nothing happens and nothing is deleted.

A UAC (User Access Control) prompt is the prompt you get from Windows when you try to do something that requires admin rights.

I think all your symptoms are related and it seems like a permissions problem.

My advice to you at this point: make a backup of all your settings, themes and icons, then uninstall Nexus Ultimate completely.

Now, download the latest version of Nexus Ultimate from the Winstep web site (https://www.winstep.net/ultimate.zip)

Unzip the setup file onto a folder.

Don't run setup by double clicking the exe, instead right click UltimateSetup.exe and select "Run as Administrator". Make sure you get a dialog asking for permission to run the installer.