This is only applicable to FL Studio 12.5 and under. FL Studio 12.5.1 and up feature updated, 64bit native, versions of the legacy VST plugins.
Use the Browser Search feature to locate the missing FL Studio plugin and then add it to the plugin database as shown below.
NOTE: If we 'hide' plugins it's to discourage new users from using them, because we want to phase them out for technical reasons. Plugins that are depreciated usually have more modern, better alternatives among the included plugins. We recommend using one of the alternative plugins included in FL Studio over plugins that have been depreciated.
Depreciated Plugins:
Fruity 7 Band EQ
Fruity Balance
Fruity Bass Boost
Fruity Blood Overdrive
Fruity Center
Fruity Chorus
Fruity Compressor
Fruity Delay
Fruity Fast LP
Fruity Filter
Fruity Flanger
Fruity Free Filter
Fruity Mute 2
Fruity Phase Inverter
Fruity Phaser
Fruity Reeverb
Image-Line Support Team