App Not getting installed

My application user is not able to install an application on his Samsung A9 pro.
But when i change the package name of the application signed with the same keystore as former, he is able to install on the same device.

What is restricting the application to get installed? is it something to do with caching?
How to resolve the issue. Please suggest.

= Can you provide us with more details of the error. Also i would like to know was there any recent software changes done on your smartphone

Now, many people’s reckoning smartphones have become unique, which is very crucial. It feels like if you don’t have a cellphone, you can’t do anything. The following is legitimate. Getting here, technology development is also increasing rapidly, still one of them is cellphone technology. This makes the cellphone smoother in the mouth, such as NFC, accurate GPS, multitasking capabilities, and so on. This is what makes our cellphones healthy to do many things. Among them, such as working, typing, contemplating films, buying goods, until what is done most often is playing games. https://aoifeawen.blogspot.com, more and more Android Games that can be played. But not infrequently, I can’t download the game operation via Playstore. But, you don’t have to worry that you can rely on what is called a mod practice. Self-sufficiency mod engineering has its advantages, you know. Here are some of them.