As far as I know, Ubooquity has no timeout when it tries to access a file.

Either it fails right away, or it waits for the file to be available. On my own setup the disk takes sometimes 5 to 10 seconds to wake up and the browser just waits until the page is displayed.

You're welcome. :)

In the default and modern themes, a rating of 0 (which is the default value) results in the display of a transparent image (so you don't see anything, although some space is taken by the image).

Is this that empty space that you want to hide ?

As for the "null" description, did you scan some books of your collection along time ago ? (I mean at least 6 months ago)

I'm asking because there was a bug in an earlier version of Ubooquity causing this behavior.

Just updating is not enough though, you'll have to clear your ebook database (there is a button for that in the book settings) and scan everything again.

Ubooquity works the other way around: you choose for each shared folder a list of users who can access it.

So in your case, the easiest solution would be indeed to create folders dedicated to kids, teenagers, adults, and restrict access accordingly.

Just activate comic sharing in the preferences.

Well, according to the error message, your browser tries to connect to Ubooquity using HTTPS instead of HTTP.

But I don't know why. :(

That's a bug I plan to fix: Ubooquity uses the comic title to sort issues, but when the title is not available in the metadata, it uses the file name. Hence the inconsistent sorting.

I plan to add an option allowing to choose between title and filename sorting.

The 504 HTTP error is a gateway timeout. It mean that one on the servers (proxy) your request goes through is timing out.

This can mean that Ubooquity is unreachable or veeeeery slow, or that there is a problem somewhere else on the chain of servers crossed by your request.

For OPDS (and OPDS only, other parts of Ubooquity manage authentication using a different method), Ubooquity uses Basic HTTP Authentication.

This authentication method is made mandatory by the OPDS specifications, that's why it's different from the method used elsewhere in Ubooquity.

Let me know if you have specific questions about this.