Linux/windows? Listenserver or dedicated server? Go to Your console and write:
meta list
and show the contents of Your screen after that.
BTW - If you did everything correctly, You shouldn't to have any problems then, so don't think You did really everything OK.
To make sure Your all-in-one installer installed everything correctly for You, read
this topic to see what was happened in Your metamod directory and in Your plugins.ini file.