Harm of meta tag robot nofollow ???

In short, what would be the damage done to a site if it unknowingly had the robot meta tag set to "nofollow" ?

To be clear, this is the header meta tag that tells search engines to not follow ANY links on the page. This isn't the same as rel="nofollow" which tells search engines to not follow individual links (so as to not pass link juice)

Ok so for some background, I just took over a site that has struggled for a long time to rank in SERPs despite being 4 years old, interesting and unique content. No blackhat SEO, either.

For the past few days I have been going through the site, and all the programming. Lo and behold, I found the "nofollow" meta tag in the code. I am assuming this prevented search engines from following ANY links on the page, including important internal links like menu links, sidebar menu links and "recent post", etc. links.While perhaps not as devastating as unknowingly having "noindex" set on all your pages, but I am guessing "nofollow" for all the pages is pretty bad.I got it fixed and now the robots meta tag is "index, follow". Do you think I see more rankings and visitors once the search engines crawl again and notice they can actually follow all the links?

I will bet you do see a decent improvement, especially if this was used on all content pages. You should gain from internal linking at least.

I really hope I see improvement!

Yes, about 95% of the content on this site had the "nofollow" meta tag. It looks like it was a "simple" misunderstanding when they were setting up the CMS and the additional plugins. I got the site from my friend, he has worked hard on it for a few years but never really saw much growth in traffic. Never really ranked much content in the top 100 SERPs, despite some of the content being incredibly detailed. He basically gave up on it because of the lack of results.