Hello and sorry for my poor english. I’m new in Synfig and I need some help for something quite simple. I have a PNG imported and I need this object to appear suddenly in an animation. So let’s say I have just two groups: one with the PNG background and above one with the PNG character. In the Character Group I have an object masking the PNG, so you can’t see the character on the background. I need the character to appear let’s say at frame 124. How can I do it? Can I do this also with a fade effect? Thank you.
Hi and welcome here 
Did you try yo play with the “amount” parameter of your “Character” group?
Start with 0, then use 1 at frame 124.
You don’t need to use the “Mask” layer 
Welcome here Pixelut,
You can a look to the doc / wiki : Show or hide a layer, or fade the effect of a blur?