Hi,
It seems to be related to the software that is responsible for unpacking .APK files. It might also be a problem with the file you downloaded, try redownloading it from elsewhere (like substar, 0.3.0.2.1 is free public build everywhere).
If it is in fact problem with the .apk handler, then you could try to install some 3rd party .APK handler if it's to upgrade from 0.3 or 0.3.0.2 to 0.3.0.2.1 (i'd suggest X-plore file manager or App manager (green Android with spanner icon)), but if you're upgrading from 0.2.2.8 to 0.3 it's easier to just uninstall the previous version and install the new one, as save files from 0.2.2.8 aren't compatible with 0.3.
Hope this helps,
Cheers