TheFloW has updated his Vitashell to version 1.51 and it fixed some bugs with Vitashell 1.5. You can get Vitashell 1.51 from github
VitaShell 1.51 Changelog
■ Fixed bug where ‘Please wait…’ was shown instead of a specifc USB message.
■ Fixed VPK installation crash.
■ Fixed bug where ‘theme.txt’ was always resetted.
■ Updated to newest libftpvita.