Quote from
HMW on May 3, 2009, 4:16 pm
There may be an error in the Hammer entity information file for Portal, which, among other things, tells Hammer which properties and flags each entity type supports.
To refresh that information, bring up the Source SDK launch pad and select "Reset Game Configurations". (This doesn't delete your saved games, achievements or settings.)
If that doesn't help, try un-installing and re-installing the Source SDK entirely.
There may be an error in the Hammer entity information file for Portal, which, among other things, tells Hammer which properties and flags each entity type supports.
To refresh that information, bring up the Source SDK launch pad and select "Reset Game Configurations". (This doesn't delete your saved games, achievements or settings.)
If that doesn't help, try un-installing and re-installing the Source SDK entirely.