Calibre is great for managing an ebook library, and okay for reading ebooks but the reader is clearly not its primary focus, so I'm wondering what readers folks here use across platforms.
I know of a few, but I'm always on the lookout for different options that may have features I didn't realize I'd love to use.
Which OS were you trying it with? I was pleasantly surprised when I found it was available on Windows, and a simple install had it working for me. Another option to consider if it still gives issues (and you’re on Windows) may be SumatraPDF, which despite the name supports a wide range of formats.
I’m running Debian. Okular worked for smaller epubs just fine iirc, but was struggling with large textbooks which is what I was using it for (Deitel Java specifically). Took forever to load, and was sluggish to search.
Unfortunately it looks like sumatra is windows only, but I’ll keep searching!