I have a virtually empty new Joomla 3.4.0 site with only sh404sef installed and two articles. When I tried to install K2 via the Extension Manager I get
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Warning
Table 'k2_categories' doesn't exist SQL=SHOW FULL COLUMNS FROM `k2_categories`

Error
Error installing component

Thank you for installing K2 by JoomlaWorks, the powerful content extension for Joomla!
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I couldn't find any install instructions for K2. Does one do anything other than run Extension Manager install for it?

I assume the Error is due to the Warning. The site is TheWordAsGod.com

Extension Manager >Warnings also says something that probably isn't related:
The PHP temporary directory is not set.

Thanks in advance!
Tim

I found Krikor's related reply to another thread, ran phpMyAdmin and found only 74 tables with none prefixed "k2", and checked that /tmp is empty. With the same result. I am the only user, a superuser.

actually this issue is related.
If the paths to the /tmp and log folders are not properly setup the installation process will fail.

Furthermore once you have properly setup these paths, uninstall K2, empty the /tmp folder and start over.

Thanks, Krikor!

I originally used Hostgator's cPanel Quickinstall of Joomla 3.3.6, which I successfully upgraded to J3.4.0, then I successfully installed sh404sef via Extension Manager, using mod_rewrite via the J3..4.0 htaccess.txt setup. I am highly impressed with Hostgator support, and that all seemed to work fine with my first couple articles. Installing k2 was my first glitch.

cPanel File Manager edit of configuration.php shows
public $log_path = '/home2/tmccully/public_html/logs';
public $tmp_path = '/home2/tmccully/public_html/tmp';

Earlier I did delete one leftover /tmp file from it per your advice elsewhere.
I also just used file manager to create the /logs folder. It seems very odd I should have to do so.

Both tmp and logs are permission 0755
public_html/tmp is empty.

There is no K2 anywhere to be uninstalled as far as I can see. No plugin, no module. phpMyAdmin shows no K2 named tables, 74 others.

Attempted Extension manager reinstall of K2_v2.6.9.zip as downloaded. Same result.

I also just used file manager to create the /logs folder. It seems very odd I should have to do so.

No, this is not the normal procedure.

One last thing, install Admin Tool, this tool will help you correct all file/ folder permissions.

Krikor,

Are you saying that permission 0755 is wrong? What then should it be?
The file manager in my cpanel already lets me change permissions.
Do I have any reasonable option beyond starting over with Joomla install? That wouldn't be prohibitive in this case.

Thanks!
Tim

755 is correct for folders and 644 for files.
Admin Tools will enforce these permissions to ALL the files.

At this point I would personally start over.

Thanks, Krikor

I decided that was the best way to spend my time.

Regards,
Tim

Let me know how that went.

I just successfully installed K2.
My procedure included: account reset to default, Quickinstall Joomla 3.3.6, Joomla update to 3.4.0, extension install sh404sef, account backup.
I checked /tmp which had only a February index.html file in it. also /logs existed in use.
Then I installed K2 without any problems.

The only thing I recall doing differently was this time I did not use Extensions JED Add Install from Web, since I didn't find it useful earlier and something about that seemed not to be working but I don't recall what it was.

Install from Web was having issues and it was down for an extended period of time. It has caused similar issues in the past.