error message after first run

[Claus444]

Short Notice from the maintainer

After 6 years of more or less intensive programming on Calibre-Web, I need a break. The last few months, maintaining Calibre-Web has felt more like work than a hobby. I felt pressured and teased by people to solve "their" problems and merge PRs for "their" Calibre-Web. I have turned off all notifications from Github/Discord and will now concentrate undisturbed on the development of “my” Calibre-Web over the next few weeks/months.
I will look into the issues and maybe also the PRs from time to time, but don't expect a quick response from me.

Please also have a look at our Contributing Guidelines

Describe the bug/problem

A clear and concise description of what the bug is. If you are asking for support, please check our Wiki if your question is already answered there.

To Reproduce

Steps to reproduce the behavior:

1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error

Logfile

Add content of calibre-web.log file or the relevant error, try to reproduce your problem with "debug" log-level to get more output.

Expected behavior

A clear and concise description of what you expected to happen.

Screenshots

If applicable, add screenshots to help explain your problem.

Environment (please complete the following information):

• OS: [e.g. Windows 10/Raspberry Pi OS]
• Python version: [e.g. python2.7]
• Calibre-Web version: [e.g. 0.6.8 or 087c4c59 (git rev-parse --short HEAD)]:
• Docker container: [None/LinuxServer]:
• Special Hardware: [e.g. Rasperry Pi Zero]
• Browser: [e.g. Chrome 83.0.4103.97, Safari 13.3.7, Firefox 68.0.1 ESR]

Additional context Add any other context about the problem here. [e.g. access via reverse proxy, database background sync, special database location]