Follow up to the problems with loading lst files…
Could you provide more details?
How/When did it happen?
Can you reproduce the error and list here the steps to trigger this bug (like you did in the other issue you posted)?
Rodolfo,
One of my students got this message and I can’t reproduce this error - well, I can recreate only by manually killing the rendering process 
. After this feedback, the student rendered the file without problem…
My class is home based now and I can´t really have a first hand account of the setbacks happening with Synfig.
If you have some time and check the thread below you’ll be amazed by the strange Synfig behavior on my students machines. I couldn´t reproduce the errors and every single time, with the same files, synfig works fine with me on my personal computer and with other four machines I have tested in my school - some OLD i7s series 2 and 3 with win 10 and 7…
Thanks you for your support!
I ran into this issue as well. Stopping another process running on the computer and restarting the program seems to have corrected it.
I was not able to reproduce the error after it was fixed.
What is your Synfig Studio version: 1.4.2 or 1.5.1?
What was your target/codec: ffmpeg/avi/gif/… ?
I’ve got 1.4.2, and I believe it was avi.