B-D-H, I wanted to look into this further for you. What version are you trying to run and on what device.
If you can narrow down more information about this we would be happy to solve the problem for you.
Viewing post in Stealing a Monster Girl Harem comments
Version 1.1.6(I think.. this was only a few days ago..) for Android..also the download states 1GB but after it was complete it's becomes 1.5GB even tho that shouldn't matter but it might. Everything seemed to download ok, and as it began to unpack it got to what appeared to be 75% and then gave me an error saying it couldn't be opened. I did double-check to make sure there was plenty of space available, it was. Then tried again with the same results
No I'm still getting the same error, but I think I found why it is giving me the error.
I have purchased all of cherrykissgames' visual novels, and still have them installed so I deleted all of them. I tried to install Stealing a Monster Girl Harem again, and it finally let me install it. I started re-downloading all of the other visual novels, and reinstalling them. When I got to Monster Girl Breeder it was giving me the same error. I than went to the downloaded apks in my download folder I noticed that the names for Monster Girl Breeder (com.cherrykissgames.monsterharem-1.2.5.apk), and Stealing a Monster Girl Harem (com.cherrykissgames.monsterharem-1.1.7.apk) were exactly the same except for the version number (1.1.7 & 1.2.5). I tried renaming one to see if that did the trick, but I still got the same error. So I believe that both apps are somehow being recognized as the same, which is why I'm getting the error of it being an update.
I have sent them an email, and hope I get a response soon. I know I could just delete one of them when I'm done playing it, but I kind of like leaving it installed if I ever want to go back to it.