What Does "cannot read item cafebabe-cafe-babe-cafe-babecafebabe" Error mean While uploading package

Above Error mean that You are not logged in as Admin user before uploading the package.

Regarding package share you could also get error "Item cannot be saved because it has been modified externally"

If you are getting this error in CQ5.3/CRX2.0 -- Solution would be to go to CRX explorer and then click on revert all on the top. Or navigate to uploaded package under /etc/packages and then remove that package.
Good solution would be to upgrade to CRX2.1/CRX2.2

If you are getting this error in CRX2.1 -- As a workaround you can touch this package again by going to package share -> Then select that package and then click on rewrap. Also you can try to use CQ package manager instead if nothing works.

Reason why you get this error because CQ package manager interfere with CRX package manager (Disabling any one of them will resolve this issue permanently ) when you install a package. I have not this issue in CRX2.2.