Issue: Wiki CSS does not work after NuWiki import

You need to rebuild your style information. AdminCP > Styles & Templates > Style Manager > Rebuild All Styles. Or, Maintenance > Update Counters > Rebuild Styles.

I don't think this was related to the NuWiki import since that isn't designed to modify style information in any way. Is it possible that you recently installed, upgraded, or uninstalled another modification? Edited any templates? Modified any CSS? Did you use the standard vB admin scripts or another script entirely?

That's only if the CSS is actually missing. It's possible that it's being loaded to the page, or is in the wrong format. In this case, I may be able to diagnose if I had a link to an affected page.

Rebuilding styles does not help. There is a working CSS file and the forum looks like it should.

Because this is a copy of my live board, I still had a replacement variable for clientscript in place, which made the JS files unreachable. Removing this did not solve the problem, but now the links for 'history', 'edit', 'watch', etc are replaced with one 'more...' button.

In my showthread and forumdisplay template I did remove the forumheader edit of NuWiki, as that's needed to uninstall.

Because the Wiki forums do not display nice like my other forums, I tried disabling Sorky - subforum manager. That had no effect, so I re-enabled it again.

I sent you login details.

Most of this is now resolved by this action:
VaultWiki > Wiki Style Manager. For each style, open Wiki CSS, and click Save. This should recreate the CSS file.

The vbulletin edit button still floats around.
How do I turn off the forum headers in showwiki.php?

How do I expand the Table of Content width? Currently the chapter titles are cut of and continued on the second line.

The table of contents width is set in template vw-important.css under .special_toc
You probably want to change this to min-width

I have set this to 500px.

Not sure what you mean about the "edit button floating around"
Also, there's not currently a way to have headers enabled in the forum and off in a thread.

Click the header dropdown arrow.
Then I would like to suggest that feature.

I think this is a known issue, where upgrading vBulletin 3's style system just isn't as extensible as vBulletin 4's. I'm surprised I didn't think of this before, but it should be possible to fall back to inline CSS if the wiki field is empty.

Fixed for the next build. When the wiki CSS is empty (or not stored as files), it will default to loading the CSS not as files, constructed by and passed through a wiki_css.php script. This allows the CSS to work correctly on a given style, on LTR and RTL languages at the same time, which was a problem overall with vBulletin 3's CSS caching mechanism.

This should prevent the CSS from ever failing on vBulletin 3. Also, when CSS is not stored as files, saving CSS edits are faster.