This kind of error messages can appear if you try to install a package whose previous installation got aborted without completing.
rpm by default won't install a package if any of the file it needs to install already exists in the filesystem. So, if a previous installation aborted and some files were left behind, all succesive attempt will fail. The error message is quite confusing because
rpm will try to find out which package the problematic file belongs to and in this case, it's the very same package it tries to install. The
--force option tells
rpm not to care and erase what it needs to perform the operation (that's why it may be risky, but if no other package claims the file, it's safe).