Thanks again for your help. I did exactly as you told me (the interface is not the same as usual, so I think everything is quite new compared to my environment in other projects). So I still get the error messages. You can see on the attached screenshot :

CIN_CONFIG=/home/chapolin/Plop/bcasttem /usr/bin/cin

Like @andreapaz , I have attempted to create a scenario that gives me a LOG message popup based on the information you provided.  Still, I get no errors and it works correctly.  Below is my file on /tmp which I named "test.sh" and the png files were just legitimate png files of a circle.

PNGLIST
12.500000
1280
720
/tmp/00.png
/tmp/01.png
/tmp/02.png

Only if you have time, could you try just this simple case with the above in a test file and (if you want to) substitute /home/moi/anim instead of /tmp.  First, create the 0x.png files using what I have attached here just so that we are doing the exact same thing.  Then load test.sh using the strategy of "Replace current project".  BE ABSOLUTELY SURE you don't already have something you are working on or it will get replaced and you may lose work.

If the above test works and no error LOG popups, then there is something in your case I am unable to diagnose that is wrong. If it does not work, a second test to try this again after starting up Cinelerra using a temporary startup file -- type in:    CIN_CONFIG=/tmp/bcasttemp ./cin/bin   (where ./cin/bin is whatever you use to start Cinelerra, like the AppImage name).

but in your case they seem to be images

Yes, it's a .sh file that points to a folder containing png images to create a stop-motion animation.

I followed the instructions on this page dedicated to cinelerra-cv: Stop-motion

They advise naming the file with the .txt extension but it doesn't work. I've found, I don't remember where in another tutorial, the advice to name the file with the .sh extension and it works very well.

Here is an example of the file used:

PNGLIST
12.500000
1280
720
/home/moi/anim/00.png
/home/moi/anim/01.png
/home/moi/anim/02.png
/home/moi/anim/03.png
/home/moi/anim/04.png
/home/moi/anim/05.png
/home/moi/anim/06.png
/home/moi/anim/07.png

@andreapaz

I looked at your screenshot more carefully and now I see that you have "real" image files that have a ".sh" extension - usually the .sh extension represents shell commands but in your case they seem to be images !!  The solution I proposed was meant for rogue files that were actually shell commands and should not have been there so does not apply in your scenario.  I can not track where the error message you see of "file not found" is actually coming from and could be only because of the unusual .sh extension.

Your solution of ignoring the LOG file may be the only solution.

The following worked but you must be VERY CAREFUL:

1. make 2 backup copies of your Project file

2. very carefully or YOU COULD LOSE YOUR WORK, edit your project file and look for the section <ASSETS>.  After this line you will see the mistake files that are giving you the error messages.  Generally each file has 5 lines -- delete these lines for the mistake files.  The lines to be deleted begin with the following and end with the next.

  <ASSET SRC=...     is the first line and the last line for that mistake file will be:

  </ASSET>

My previous suggestion did NOT work so I deleted it.  I will experiment some more and maybe Andrew-R has a good solution.  It was to File pulldown, Save as... the project again or File pulldown, Save backup -- it did not work and the error was still there.