When you download the game here on itch, there should be a section with installation instructions that shows a workaround to get over that. Unfortunately, I'm not entirely sure why that happens.
Instructions for the workaround:
Android:
- 1. Download
- 2. Install apk
- 3. Play
To install on android:
1. Open the apk file and pick "Install"
2. When you see the unsafe app blocked, pick "More details"
3. And then "Install anyway"
4. Start the app and when asked to check for security pick "Don't send"
To not lose your saves on android after the update:
If you have played an older version of Nothing is Forever and want to make sure you don't lose your older saves:
1. connect your phone to your PC and go to: Android\data\com.mrsilverlust.nothingisforever\files
2. Backup the folder named "Saves"
3. Update the app (if you get an error, check info below)
4. After updating, go again to:
Android\data\com.mrsilverlust.nothingisforever\files
and past the "Saves" folder there
5. Play the game with your old saves
Error while updating app:
If you are updating from an older version of Nothing is Forever, you may see this error:
If so, you need to delete your older version and install the apk file again. Don't forget to backup your saves first or you will lose them!
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So:
1) If you don't want to lose your old saves, you'll have to first back them up as mentioned in the instructions above.
2) Then, delete the app version 0.7.1 you have currently installed.
3) Install the app 0.7.3 from scratch. It should now complete the instalation.
4) Copy the old saves folder you backed up earlier to the correct folder, as explained above.
5) Play!
If you don't mind losing old saves, just delete the old app and install from scratch the 0.7.3. This will delete all your old progress, though!! So, I'd advise to save the saves first.
Hope this helps.