epub file too large?

I'm working to combine shorter stories into 'collections' so that I have all the connected stories in a series in one file. This has been great.

I just finished one, closed the file, then realized I forgot to have Sigil generate a TOC and now Sigil won't open the file. It just crashes as soon as it tries. It'll open other files, but not this one.

Is there a file size maximum?

I'm on Windows 11, using Sigil 2.3.0