Due to nginx configuration, this may happen. Increase the size in nginx and set the client_max_body_size limit. Odoo's default limit is 25 MB, so it should allow uploading this file
If you are using Nginx.
Then you can resolve this issue by adding a line to the nginx.conf file and then restarting Nginx.
Set it in the HTTP block that affects all server blocks (virtual hosts). In Ubuntu, the nginx.conf file can be found at /etc/nginx/nginx.conf
http {
...
client_max_body_size 100M;
}
This way, it can be resolved.
Note that after modification, you need to restart the Nginx service
sudo systemctl restart nginx
