Answer
This is commonly caused by a space somewhere in the Oracle Home environment variable's path or name — when the installer/importer encounters a space in that value, it stops reading at that point and effectively truncates the path, which breaks the operation. Fix it by editing the Oracle Home environment variable (via System Properties > Advanced > Environment Variables) so it contains no spaces — using only alphanumeric characters, underscores, hyphens, or dots, and starting with an alphanumeric character — then retry the import/installation.