安卓开发错误1

Failed to finalize session : INSTALL_PARSE_FAILED_MANIFEST_MALFORMED: Failed parse during installPackageLI: /data/app/vmdl920494270.tmp/base.apk (at Binary XML file line #20): <activity> does not have valid android:name

解决办法这个activity的前面需要加一个.号缺了不行。