500 Internal Server Error - server encountered an internal error

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500 Internal Server Error

Internal Server Error

The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

how to solve it and all user mails not shown in admin panel and not login on rouncubemail

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how to check “/tmp” exists as well

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Internal Server Error

The server encountered an internal error and was unable to complete your request.
Please contact the server administrator if this error reappears multiple times, please include the technical details below in your report.
More details can be found in the server log.

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Did you check the server logs? Probably something in /var/log/nginx/error.log or /var/log/syslog.