@Anas Sayed, Thanks for posting in Q&A.
I have done some research about the error, here is the information you can refer to fix the issue.
Could you please confirm that the app has the android:versionCode string in the AndroidManifest.xml file in your APK package? It is possibly due to string is missing. So that seems to be the reason.
Please try above information, if there is any update, feel free to let me know.
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