Failed to save file error

Hello I have this error when I make my modifications on a page. How to solve this problem

It must be something wrong on your server side. Please take a look at Grav file permissions in the troubleshooting section of the docs.

all my old pages I can edit them but it is only the new blog page which displays this error. I have to execute which command to fix it in the lunix machine.
thank

Did you try the "fix permissions script" which is in the doc page I mentioned:

chown -R joeblow:staff .
find . -type f -exec chmod 664 {} \;
find ./bin -type f -exec chmod 775 {} \;
find . -type d -exec chmod 775 {} \;
find . -type d -exec chmod +s {} \;

Be sure to replace 'joeblow' with your Linux username.

If the script doesn't help I'm afraid I can't help you either.

I have to run or the script where in the root of my grav installation ?.thanks for the help

Yes I think so.

(This text is just to pass the minimum post length of 20 characters.)