Same problem.
Joomla 2.5.11
K2 2.6.6
Have many other sites with K2 on this server - no problems.
On this site K2 menu in Components menu don't displays.
Site and browser cache cleaned...

Hello romagromov,

Are your permissions setting correct? You can check your configuration file and permissions through the System Information menu item.

Also try disabling the system cache altogether and tell me what happened.

My premissions is Super user.
Premission for folders are OK.
joomla minimal requirements OK.
All cache plugins are disabled.
System cache disabled.
Browser cache cleaned.
I tryed to reinstall K2 several times (older versions and latest).
Only K2 admin modules displays.
K2 menu don't displays.

In mysql base K2 menu item looks ok.

Ok... Lets try a long shot..

Go to extensions => module manager and select the administrator modules.

Locate the admin menu module and toggle caching for this module.
You can even try to deactivate/re-enable this module.

If you deactivate it dont lose your page URL because you will have to activate it again from your DB.

Let me know how that went.

Ok, I did all steps you suggested.
I can't find option to toggle caching for this module, but it seems this module don't use caching



Also I tried to disable/enable module - no results...

Unfortunately I am not able to reproduce the issue.

You told me it works fine on all your other installations, so did you follow any different steps this time?
Any other extension you have not used in your other sites? Is this the first install or is was it an upgrade and finally did you unistall K2 at some point and reinstalled it. Have you disabled any K2 plugins?

Sorry for asking you all these questions and sounding like the holy inquisition but I want to reproduce the issue.

It very strange, but after several hours, K2 menu item displayed without my intervention...
I installed K2 many times on many sites before, but I have never seen same issue before.

You told me it works fine on all your other installations, so did you follow any different steps this time?

Usually, I install K2 after joomla installation. But this time, I have installed couple components and plugins: FlexiContact, Jdownloads, Advanced Module Manager, JCE, Xmap, SEO Links, e.t.c.

Any other extension you have not used in your other sites?

Yes, FlexiContact and Jdownloads I use only on this site.

Is this the first install or is was it an upgrade and finally did you unistall K2 at some point and reinstalled it.

First install. But after I got this issue I tried to reinstall several times.

Have you disabled any K2 plugins?

No, never.

Same issue here. K2 2.6.6 on J! 2.5.11
tried to reinstall with no luck.
There are icons, not the Component menu

Got same crazy deal on J2.5.11 (updated from 1.7.3):
No K2 menu-points shown in Joomla 2.5 administrator menu "Components"

Anyway everything looked fine in the database...

Not sure what did fix it:
I went to the Extensions Manager -> Manage
Filtred by "K2"
Unpublished the K2 (component) -> check-marked the unpublished component
Clicked "Refresh cache" -> Published the K2 component again
and I got my K2 menuitems in the admin components menu
:woohoo:
Which of the above steps did it I do not know...
Hope it might work for others

Maybe this can help you all.
For me it was a language issue. I was using a mix of english and italian in backend. After set frontend and backend with italian I see K2 component menu fine.