Hello @NathalySuarez_25
In the web.appsettings.config config file located in /var/www/onlyoffice/WebStudio/web.appsettings.config you have to paste next string:
<add key = "web.available-file-size" value = "524288000" />
where value defines the size of the opened file in bytes.
After making any changes to the config file please execute next command to restart the service and to apply the changes systemctl restart monoserve