How do I know I can trust the integrity of flt sim managers scenery diagnositcs? Its an old program and scenery technology may have changed, how do I know when I have it "fix" the problems that it is not causing new problems?

A complete backup of your FS9 installation.Thats the answer, if you maintain a good backup of your FS9 then you will never worry :)That said I use FS Manager regulary..specially its scenery-fixer. It tidies up the scenery.cfg nicely. It also makes a backup of it before it does its thing so there no problem - its never given me any trouble but I have to say I hae *only* used its scenery-fixer function.

The main thing I've found is not to accept the landclass recommendations willy-nilly. the general concept is OK (putting landclass in texture folder-less scenery areas).scott s..

I see, I use it for its scan for errors with scenery configuration problems function, it usually detects layer mismatch things.

It works just fine for layer mismatch problems... I usually fix them manually after letting FSM do the diagnostics. It's tedious, but too many weird things can happen for FSM to be depended on to fix all of them.DJ

Are there not a number apps called 'Flightsim Manager'? Which one is being discussed here?

I think its the one made by Ranainside :)