Most of the parameters listed are invalid or non-canonical. For example, the following are simply not valid:
&_do=comments
&_amp_amp_do=comments&langid=3
&langid=3 does nothing in XenForo.
&redirect=no is only visible to logged-in users in VW3 anyway.
No matter what the parameters are, the redirect scripts are only designed to point to the main tab of a wiki page.
title=Island:177466
This URL will not work if that Anonymous page no longer exists. On your old site, look for showthread.php?t=177466
It was either deleted before import or after import. There is an edge case of Island URLs that would not have been imported correctly:
- In VW3, you created a redirect in an Island-type forum.
Looking at the code, I think Island redirects would be imported as synonyms with Prefix = [No Prefix] and Title = [threadid], which is a bug. Island redirects should be imported with the Island prefix merged to its title; that is, Prefix = [No Prefix] and Title = Island:[threadid]. If this happened, it should be easy to find in Special:ListRedirects, because the number titles would be first in the list. You could then modify the affected synonyms and rename them so that "Island:" appears at the beginning of the number-title.
You did not specify what types of crawl errors each are. In many cases, a "403" is good. It means that non-public content is not being shown to guests.
Since this is due to a bot crawling the site and actually finding these links, you should pay attention to where the bot found them and correct the invalid links. You can easily have "404" crawl errors on your site if your users post made-up links or if you later delete the content that they linked to. This is all expected behavior.
If any crawl errors are due to "500", this is a different problem, such as a PHP or MySQL error at the link, and is probably not due to a flaw in the redirect script.