Hallo together,
when I import a .mp3 file and want to open the synfig file again, I got a mistake message:
Mistake while opening the file
Maybe related to the synfig projet file format you have used. Did you have saved your project under .sifz or .sif and moved your mp3 file ? : How Do I fix a synfig document.
Hallo d.j.a.y.,
ich don´t know, what I did. But I have made some experiences. When I saw, that if must be possible to save a projekt with a sound file, I tried it again, bau with a .wav file, and it functioned.
I will have another try with synfig, but I am a little bit afraid, that it will happen after a lot of work again. If it happens again, could I send the file to here, so that you could help me.
Thank you
Rudl
Always define a relative path instead of a fully qualified path for files of resources.
Resources should always reside in the same directory than project file, and so, you could make your whole project as “portable”. 
What is better?
I will save in future all my files in the same folder.
Thank´s all for help.