The "Unable to install applcation" error message on your Ledger Manager is displayed for several issues:
not enough space on the chip OR something avoiding the Ledger Manager to recognize how much space is left on the device.
- when the application you want to install is yet installed on the device. To update the application, uninstall it first by clicking on the bin icon, then reinstall it by clicking on the green arrow.
- when there is not enough space on your device to install a new application, it is easy to uninstall and install new ones.
You can install about 5 apps at the same time on the Nano S, and 8 to 10 on the Blue, sometimes more. This space depends on which apps are installed on your Nano S, and on which order you chronologically installed them.
If you can't install a new application even if you have less than 5 apps, you should uninstall all the ones that are installed, and reinstall each one you need successively.
Please follow this guide to understand your issue https://ledger.groovehq.com/knowledge_base/topics/unable-to-install-dot-dot-dot-error-message
You can manage more applications, even if they are not all installed at the same time, using the Ledger Manager, by uninstalling and installing apps when you need to use them. These steps take few seconds only. Don't worry, even if you uninstall an application, you won't lose your coins, you will be able to connect and synchronize your accounts next time you'll install and open the application.
If you want to have all your applications available without having to uninstall some other ones, you can of course also deal with it using a second Nano S.
- when you don't achieve to install new applications whereas you have less applications than possible, you need to uninstall all the applications and reinstall your apps one by one successively, in the limits of the memory of your chip.
If you need to use more applications because you manage a lot of different coins, the Ledger Manager will be the interface to manage your applications each time you need it, by uninstalling and reinstalling them. Even if it is a bit tedious, these steps only take a few seconds.
Don't worry, even if you uninstall an application you already used, your coins won't be lost. Uninstalling an application from your device won't erase your wallet and the coins you already have on it. You'll be able to access your wallet anytime by reinstalling the application.