The more articles, the more pages with pagination
How do I fix this?
How do I configure to make it for example "1.2.3.4.5 ... 15"
thanks in advance

K2 uses Joomla! pagination, so you need to change this function in Joomla! core files (or better - use overrides).

Changing core file:

1. Find 'your_site_root/libraries/joomla/html/pagination.php'.
2. Find:

// Set the pagination iteration loop values.
$displayedPages = 10;'

3. Change it to (for 5 pages):

// Set the pagination iteration loop values.
$displayedPages = 5;'

Done.

To use overrides you must copy file to your template folder ( 'your_site_root/templates/YOUR_TEMPLATE/html/' - but if your template uses this file (some templates do), better change your core file.

Jakub Jedynak thank you very much for that help, you saved my project.

I have followed your steps and it worked until I came across this error by clicking on page 5, it looks really weird!
Any solution?

jack

I'm sorry but I have no idea. I tried to reproduce this but I'm unable to do it.
Maybe you are using template that have it's own pagination extra code? Try to look for "pagination" file in '/tempates/YOUR_TEMPLATE/' folder. :-(