Hi there,
I really need some help and would be very grateful for any help. I'm working on a site for a client which is still in development, you can see it here:

http:// www.labplant-zematra.com/joomla/

The site was fully working before the last Joomla upgrade.

The site is built of items within K2, and the menu system points to the pages as usual.

When you click on one of the menu items (Applications, for example) you then get a list of items within a category. The main menu items have been set to show items within a K2 category. I have added the category on the 2nd page of the menu item link.

You will now see that if you click on one of the items, it takes you to a 404 error page rather than to the item. As mentioned above, this was all working fine up until the last Joomla update.

I have turned on the Joomla SEF, and turned off the K2 SEF options. If I turn them on separately and then click on one of the items in the category list, I get taken back to the index page.

I really need help on this so would be very, very grateful for any input.

The site is using the latest K2 and Joomla 3.7.5.

Hello Mike,

Are you using any redirects?

Hi there,
Thanks so much for the reply, I really appreciate it.

There are no redirects no. It was all working, but the client has sat on it for months. When I came back to it yesterday, it was suddenly not working.

The only changes that I can think of are these:

1. Upgrade of Joomla to 3.5.x
2. Upgrade of K2
3. The site uses DJ-Mega Menu. You have to put specific aliases in for any given menu item. I thought that this could be the issue. However, I took one of the aliases out of the equation and it made no difference.

If I turn off the Joomla SEF, when I click on one of the category list items in K2, it redirects me back to the home page. If I turn it back on, I get the 404 error message.

Turning the K2 SEF on or off makes no difference. This is when the Joomla SEF is either on or off.

I spent hours on it yesterday trying to figure out what is going on. The Joomla site is sitting in its own folder as a sub-directory, but again it was all working there before.

When I hover over a K2 category link, I can see the url it is trying to reach, but it is looking in a folder that doesn't exist?

I'm totally at a loss, but I'm at the point where I need to get this site completed, so this is critical.

I would be so very grateful if you could help me out here.

Quick update. I'm confident it is not to do with the Mega Menu.
I created a new menu link in the root menu and then tried to click into a K2 item from that category list. The same issue with 404 occurred.

I also made a brand new menu using Joomla's menu system and then linked it to one of K2's categories. I then clicked on a link in that category via the menu and it still gave me a 404 error.

I can reach a K2 item's content if I use the search function (native Joomla) and then click on a search result item link.

Sorted it out. You'll be pleased to know it wasn't a K2 issue!

The issue came about due to the menu system and aliases.

Can you share with us what you did to mega to fix it?

Sure.. but it's boring and silly....

I started this site for the client over a year ago, but it has just sat there as the client has not sent over all the content.

Last year I used a different menu, and it required you to change the alias of the menu items in order to put them into multi-columns.

I must have realised this was a bad idea last year and dumped that menu. It got dragged onto another job and didn't get around to putting the menu back to how it should be. I realised this week that the DJ Mega Menu did not require this to make multiple columns. So I went back into the menu and deleted all of the wring aliases and then it worked.

Took me hours of back-engineering to find it - but then it always does I suppose, that's how you learn!

Hi there,

I would add some further info about the problem of K2 categories links not working, as I thought that the update to v.2.8.0 was definitely destroying my test site, so that I had to overwrite it with a clone of the production site and restart from the beginning.

After a dramatic website crash due to a first update from J3.6.5 to 3.7.0, I delayed the 3.7 to better times and always test any update on my test sites (www2.mydomain.tld) and thus I tested the K2 v.2.8.0 on one of them, that, for rather obvious reasons, is always configured with system debug.

After the update, I created a new K2 category link on the Megamenu (template t3_bs3), and the result was a terrifying error box titled:
"Serialization of 'Closure' is not allowed"
... following, a long list of errors on several details.

After having cleared several times all existing caches, the error was always there.

Today, after reading this thread, a light bulb lit up... I turned off the system debug, cleared again all caches and retried the link: magically, the error disappeared and the category with a test post was perfectly shown.

I guess there was some conflict with debug mode being already active, that was auto-solved after deactivation; by the way, being curious, I reactivated the debug mode and the menu link now still works like a charm.

The above with J3.6.5 and PHP 7.3... Now, the template maker sent me an update including J3.7.3 and VirtueMart 3.2.3, as I was warned to apply major updates only after a stable and tested package has been released from his side.

Now, I feel more comfortable in proceeding with this general update and wrote this post thinking that my experience may result helpful to everybody.

... I would add my conclusions:

1. always use a test site, a backup is not enough, as you could get a broken site for all the time required to revert to the previous configuration.

2. keep in mind that the debug mode introduces variations of the code rendering that can cause unpredictable effects, capable to make you waste a lot of time in trials and investigations.

3. the 2.8.0 update works, if you can bypass the possible initial problems, as the ones I met; the split of the post editor in intro and full text is useful and comfortable; still remains, at least for me, the strange behaviour of the [Save] button, that never works after loading a new image, until the editor is "unlocked" by right-clicking on an empty space of the window.

Thank you for sharing your thoughts.
Can you share a screenshot (or cast) of the issue #3?