Like many other people, we use the Contact Form 7 plugin. It's great! Easy to use! We have it installed on about 50 or so sites. Since the 4.8 version (i think that was the one) of CF7, nearly all these sites have had some type of problem with form submitting. They all have different themes and there are plugins common to all but some use completely different plugins. With the exception of 3 sites, they're all hosted on the same server. Notably, the comment forms on the blogs all work. If a problem arises, it is exclusively with the CF7 form.

So, we ran through the troubleshooting guides and a myriad of forum posts and the only solution we have found is to revert back to the 4.6.1 version of CF7. I found that as a solution on one of the forum posts. I have no idea why that works but it does. There is something going on, be it a change in the WP platform causing a conflict or something with the CF7 plugin.

In the interest of helping the WP and CF7 community figure out what is going on, I wanted to submit this as the results of what we found after hours and numerous sites. I believe this was suggested to the author but I don't know that it resulted in any change.

Anthony – December 22, 2017 9:11 pm

Hi – I can see that you put quite a bit of time into your email, so I wanted to respond.

I'm absolutely 100% sure that the problem is not caused by a fault in Contact Form 7 (CF7). The problem is caused by something or several things on your particular WordPress setups. It could definitely be related to how you have setup your Contact Form 7 forms, but it's not the plugin itself.

We are currently using Contact Form 7 (version 4.9.2) on over 50 sites on two different servers. Your email was just one example of dozens we receive every day sent via Contact Form 7. Contact Form 7 works; it has done for years, flawlessly without problems, over all versions since we started using it.

I understand you found a solution that worked for you in a forum post & it's very hard to look past that.

But with well over 6 million active installs of Contact Form 7, it's relatively easy for me to find numerous forum posts that explain very convincingly that every single version of Contact Form 7 no longer works & if you switch back to the previous version your problems will be solved. I answered 1000's of questions in the Contact Form 7 support forum over several years & saw many such forum posts each & every time Contact Form 7 was updated.

And of course it works for some people, because when they revert back something else changes that solves their particular problem. With so many active installs it only takes few people getting a positive result & saying this worked for them to convince many others that reverting to some particular version is the only answer.

Any way that's what I think. I expect you may not agree & I'm glad you found a solution to your particular problem by sticking to on older version of CF7. I'm unaware of any security issues with any older versions of CF7, so I see no problems with you doing that.

Neil Murray – December 23, 2017 3:55 pm

Hey Neil

Thanks for the reply. I agree that the fault is not with CF7. I mean, there are so many moving parts on a WP site that it could be any one of a number of things and the plugin is used on 5M+ sites! If EVERYONE is having a problem, yes, the fault is likely with the plugin. Probably haha. But not if a relatively small number are having problems. As you said, it has to be in the setup. I think the most likely culprit(s) is/are conflicts with other plugins, but I'm not developer-smart enough to be able to nail that down (I still use my fingers to count haha) so don't have any hard evidence.

Interestingly, yesterday afternoon one of my developers took the time to trace common plugin usage on dozens of our sites. We really need to get and easy way of tracking what plugins are used on which sites instead of logging into the admin, but that's another topic haha. He discovered that if a site was having a CF7 submission problem AND it used WP-Spamshield (https://wordpress.org/plugins/wp-spamshield/), disabling that plugin eliminated the submission issue. Of course, as you probably know, Spamshield had a falling out with WP and is no longer listed in the repository, but some of these sites were having submission problems 6 months before all of that hit the fan. So I don't think the submission issue is related to that. However, there seems to be some conflict between the two plugins. I doubt we'll track it down because a) not developer-smart enough (see above) and, b) not enough hours in the day.

I wish we could help the author because it's not like this is a paid plugin. I mean, the author is maintaining it and forum supporting it for free! I don't know how he does it!

I can't figure out why this would suddenly happen with 4.8.0 (i think that was the version)? Why does 4.6.1 work? When a site is having a CF7 submission issue, why does the default WP comment form continue to work fine? Is it a captcha conflict? Did WP change something to lock down the REST api (I don't even know what that is haha) and CF7 has trouble accessing? These are rhetorical questions, of course, and just some of the things with which we grappled as clients were screaming at us that their forms didn't work (they can be so mean! haha).

In any event, that's something we'll be exploring going forward. Hopefully, we'll be able to solve it because CF7 is great! Sorry for this loooooong reply. If you made it this far, you're a trooper! haha

Thanks Neil

Anthony – December 23, 2017, 10:32 pm