Hi @jnugent. Nice to meet you! These are my lines at error.log file, not sure but I think it´s not related with my problem:
2021/12/23 08:36:13 [error] 57440#57440: *8683405 FastCGI sent in stderr: "PHP message: ojs2: 404 Not Found" while reading response header from upstream, client: 172.16.16.200, server: revistas.unc.edu.ar, request: "GET /index.php/testimonios/article/download/25744/Art.4%20Giudice%20Navarro_archivos/image003.gif HTTP/1.1", upstream: "fastcgi://unix:/var/run/php/php7.4-fpm.sock:", host: "revistas.unc.edu.ar", referrer: "https://revistas.unc.edu.ar/index.php/testimonios/article/download/25744/30709?inline=1"
2021/12/23 08:36:13 [error] 57440#57440: *8683407 FastCGI sent in stderr: "PHP message: ojs2: 404 Not Found" while reading response header from upstream, client: 172.16.16.200, server: revistas.unc.edu.ar, request: "GET /index.php/testimonios/article/download/25744/Art.4%20Giudice%20Navarro_archivos/image002.jpg HTTP/1.1", upstream: "fastcgi://unix:/var/run/php/php7.4-fpm.sock:", host: "revistas.unc.edu.ar", referrer: "https://revistas.unc.edu.ar/index.php/testimonios/article/download/25744/30709?inline=1"
2021/12/23 08:36:13 [error] 57440#57440: *8683410 FastCGI sent in stderr: "PHP message: ojs2: 404 Not Found" while reading response header from upstream, client: 172.16.16.200, server: revistas.unc.edu.ar, request: "GET /index.php/testimonios/article/download/25744/Art.4%20Giudice%20Navarro_archivos/image005.jpg HTTP/1.1", upstream: "fastcgi://unix:/var/run/php/php7.4-fpm.sock:", host: "revistas.unc.edu.ar", referrer: "https://revistas.unc.edu.ar/index.php/testimonios/article/download/25744/30709?inline=1"
2021/12/23 08:36:13 [error] 57440#57440: *8683412 FastCGI sent in stderr: "PHP message: ojs2: 404 Not Found" while reading response header from upstream, client: 172.16.16.200, server: revistas.unc.edu.ar, request: "GET /index.php/testimonios/article/download/25744/Art.4%20Giudice%20Navarro_archivos/image006.gif HTTP/1.1", upstream: "fastcgi://unix:/var/run/php/php7.4-fpm.sock:", host: "revistas.unc.edu.ar", referrer: "https://revistas.unc.edu.ar/index.php/testimonios/article/download/25744/30709?inline=1"
2021/12/23 08:36:13 [error] 57440#57440: *8683415 FastCGI sent in stderr: "PHP message: ojs2: 404 Not Found" while reading response header from upstream, client: 172.16.16.200, server: revistas.unc.edu.ar, request: "GET /index.php/testimonios/article/download/25744/Art.4%20Giudice%20Navarro_archivos/image010.jpg HTTP/1.1", upstream: "fastcgi://unix:/var/run/php/php7.4-fpm.sock:", host: "revistas.unc.edu.ar", referrer: "https://revistas.unc.edu.ar/index.php/testimonios/article/download/25744/30709?inline=1"
2021/12/23 08:36:13 [error] 57440#57440: *8683425 FastCGI sent in stderr: "PHP message: ojs2: 404 Not Found" while reading response header from upstream, client: 172.16.16.200, server: revistas.unc.edu.ar, request: "GET /index.php/testimonios/article/download/25744/Art.4%20Giudice%20Navarro_archivos/image008.jpg HTTP/1.1", upstream: "fastcgi://unix:/var/run/php/php7.4-fpm.sock:", host: "revistas.unc.edu.ar", referrer: "https://revistas.unc.edu.ar/index.php/testimonios/article/download/25744/30709?inline=1"
2021/12/23 08:36:13 [error] 57440#57440: *8683427 FastCGI sent in stderr: "PHP message: ojs2: 404 Not Found" while reading response header from upstream, client: 172.16.16.200, server: revistas.unc.edu.ar, request: "GET /index.php/testimonios/article/download/25744/Art.4%20Giudice%20Navarro_archivos/image011.gif HTTP/1.1", upstream: "fastcgi://unix:/var/run/php/php7.4-fpm.sock:", host: "revistas.unc.edu.ar", referrer: "https://revistas.unc.edu.ar/index.php/testimonios/article/download/25744/30709?inline=1"
2021/12/23 08:37:46 [crit] 57440#57440: *8683680 connect() to unix:/var/run/php7.4.sock failed (2: No such file or directory) while connecting to upstream, client: 172.16.16.199, server: revistas.unc.edu.ar, request: "GET /index.php/%09%09%09%09%09%09%09%09%09%09%09%09%09%09%09https:/revistas.unc.edu.ar/index.php/drarchitettura/index%0A%09%09%09%09%09%09%09%09%09%09%09%09%09/index.php/EEH/index.php/DTI/issue/current/public/journals/92/journalThumbnail_es_ES.jpg/index.php/anatclinar/article/view/30985/index.php/etcetera/index.php/revistaadbia/index.php/notasenf/index.php/estructuras HTTP/1.1", upstream: "fastcgi://unix:/var/run/php7.4.sock:", host: "revistas.unc.edu.ar"
2021/12/23 08:40:01 [crit] 57440#57440: *8683958 connect() to unix:/var/run/php7.4.sock failed (2: No such file or directory) while connecting to upstream, client: 172.16.16.199, server: revistas.unc.edu.ar, request: "GET /index.php/%09%09%09%09%09%09%09%09%09%09%09%09%09%09%09https:/revistas.unc.edu.ar/index.php/drarchitettura/index%0A%09%09%09%09%09%09%09%09%09%09%09%09%09/index.php/EEH/index.php/DTI/issue/current/public/journals/92/journalThumbnail_es_ES.jpg/index.php/anatclinar/article/view/30985/index.php/notasenf/index.php/notasenf/index.php/notasenf/index.php/avances HTTP/1.1", upstream: "fastcgi://unix:/var/run/php7.4.sock:", host: "revistas.unc.edu.ar"
2021/12/23 08:40:42 [crit] 57440#57440: *8684033 connect() to unix:/var/run/php7.4.sock failed (2: No such file or directory) while connecting to upstream, client: 172.16.16.200, server: revistas.unc.edu.ar, request: "GET /index.php/%09%09%09%09%09%09%09%09%09%09%09%09%09%09%09https:/revistas.unc.edu.ar/index.php/drarchitettura/index%0A%09%09%09%09%09%09%09%09%09%09%09%09%09/index.php/EEH/index.php/DTI/issue/current/public/journals/92/journalThumbnail_es_ES.jpg/index.php/anatclinar/article/view/30985/index.php/index/index.php/etcetera/index.php/sendas HTTP/1.1", upstream: "fastcgi://unix:/var/run/php7.4.sock:", host: "revistas.unc.edu.ar"
I have another problem with html files, since upgrading, HTML are not loading properly, I think these are the error displayed here