If when you try to launch a UWP app on Windows 10, you notice it’s been blocked from opening or starting by your installed security software, then this post is intended to help you. In this post, we will identify the potential cause(s) to this issue, as well as provide the workaround you can try to help you mitigate the issue.
A Windows Store or UWP app is a new type of application that runs on Windows 10 and Windows 8 PCs and tablets. Unlike traditional Desktop (or classic) apps, a UWP app has a single, chromeless (i.e., no outside frame) window that fills the entire screen by default.
On Windows 10, a UWP app can start in a window, and if not full screen, tend to have a hamburger menu and a title in the upper left.
Security software blocks UWP app from opening
If your security software blocks any UWP app from opening, that is because the individual files within an application package are not digitally signed even though the packages are catalog-signed.
To work around this issue, add the affected applications to the whitelists of your security software via the program’s settings.
Digital and Catalog signatures
A digitally-signed catalog file (.cat) can be used as a digital signature for an arbitrary collection of files. A catalog file contains a collection of cryptographic hashes or thumbprints. Each thumbprint corresponds to a file that is included in the collection.
Catalog files (which you can create in Windows 10 with a tool called Package Inspector) contain information about all deployed and executed binary files associated with your trusted but unsigned applications. When you create catalog files, you can also include signed applications for which you do not want to trust the signer but rather the specific application.
After creating a catalog, you must sign the catalog file itself by using enterprise public key infrastructure (PKI), or a purchased code signing certificate. Then you can distribute the catalog so that your trusted applications can be handled by WDAC (Windows Defender Application Control) in the same way as any other signed application.
Related read: This app has been blocked for your protection.