Hello, I am new with this program and my problem is when i use my graphic tablet (Gaomon S620) , when I do click with the pencil, Synfing close. Any have one idea?
Hi and welcome here 
There are already several topics about Gaomon tablets on this forum, there is a recurring issue of compatibility with these devices.
It is not about Synfig itself, but GTK3 which is the toolkit Synfig is built on.
In some cases, updating the tablet’s driver may help (I suppose you are using Windows).
Synfig currently uses gtk-3.22.30, maybe we could try to use a version >= 3.24.31 which seems to have solved the issue.
You should have the same issue with MyPaint for example, see: