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If I change any DLL of my UWP app that I purchased from the Windows Store, will the app crash if it runs?
In most cases, if you change the DLL content or the DLL's name, the app should throw a mismatch error because the windows will check the signature of your app.
If not, what can I do to prevent attacks on my application through DLL?
The app package is digitally signed, this is the important part of security. When your app is signed, it is going to prevent your app from being able to alter the the apps functionality.
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