Kdenlive/Manual/Effects/Custom
Effects - Custom
The Custom Group in the Effects List is where Effects appear when you choose
from an effect in the effect stack.Defect in ver 0.9.2
There was a defect in ver 0.9.2 of Kdenlive where saving a new Effect made the existing custom effect invisible in the Custom section. With the upshot that you could only have one custom effect visible. This is fixed in version 0.9.3. See See this Bug Tracker Entry
The workaround in ver 0.9.2 was - Start and Stop Kdenlive. The restarting Kdenlive causes the
to be updated and you can see all the ones you have saved.(fixed)