URLS with Trailing Slash Leading to 404 Page Errors

Right now my WordPress blog (InternetTvDotCom) is showing…

184 Not found ?URL Crawl Errors…

For example: The url below is returning a 404 page error

https://internettvdotcom(dot)com/tag/ultimate-live-tv-software/

The ‘Linked From’ and’ Detected’ sections in the Google Websmaster Tools show 5 pages on Jan 9, 2012…

https://internettvdotcom(dot)com/category/internet-tv-software-mac/page/2/
Jun 9, 2010

https://internettvdotcom(dot)com/adulttv/
Apr 24, 2010

https://internettvdotcom(dot)com/category/adult-internet-tv-article/
Apr 25, 2010

https://internettvdotcom(dot)com/tag/watch-adults-channels-online/
Feb 13, 2011

https://internettvdotcom(dot)com/tag/online-adults-tv/
Apr 28, 2010

These urls return 404 errors. I deleted these tags and categories some time ago.

I’m hoping to find someone familiar with my issue that can lead me to the source of these 404 page errors so that I may correct them.

Here’s what I did on my end that caused the 404 page errors: I changed my blog theme and permalink over a year ago from /%postname%/ to /%postname%. While in the process, I also deleted many tags and categories — not knowing exactly what problems would lie ahead.

This is probably not a good idea but would like to get an answer nonetheless. Should I change my permalink back to /%postname% since I’m getting all these trailing forward slashes at the end of many urls? Most of them include a post tag and the vast majority are linking to other post urls that also have a trailing slash from my WordPress blog, InternetTvDotCom, not so much from other sites. The good news is all the urls on my site are working okay — I’m not showing any 404 page errors direct from my site because there are no trailing slashes with the exception to my domain url which works okay as well.

Or, should I go into my .htaccess file and redirect every url that’s returning a 404 error. If it’s recommended that I do this, then what code should I use and where exactly do I place it in the .htaccess file?

Also, I would like to get an answer to the following… I have my post tags setup to be indexed by Google but my post tag urls are not showing up in Google as they once did.

I have my post categories not to be indexed and as a result they are not showing up on Google which is what I want.

Once again, I’m hoping to get some help from someone that’s very knowledgeable and knows exactly what I must do to correct this issue — not from someone that’s going to take a guess at this and tell me what I could do only to mess things up further or talk above my head — I.m still relatively new to everything.

Thanks!