Hello oguzhan

It seems like you have a conflict with bootstrap.js files (probably coming from another plugin that uses Bootstrap).

Please go to wpDataTables main Settings on your wp-admin page. You'll see Include full bootstrap front-end and Include full bootstrap back-end. Disable the front-end check-box, hit Apply and refresh your page.

If this doesn't help, you may want to go to ../wp-content/plugins/wpdatatables/source/class.wdttools.php and comment the line 999:

if (!is_admin() && get_option('wdtIncludeBootstrap') == 1) {            wp_enqueue_script('wdt-bootstrap', WDT_JS_PATH . 'bootstrap/bootstrap.min.js', array('jquery', 'wdt-bootstrap-select'), WDT_CURRENT_VERSION, true);        } else if (is_admin() && get_option('wdtIncludeBootstrapBackEnd') == 1) {            wp_enqueue_script('wdt-bootstrap', WDT_JS_PATH . 'bootstrap/bootstrap.min.js', array('jquery', 'wdt-bootstrap-select'), WDT_CURRENT_VERSION, true);        } else {
//             wp_enqueue_script('wdt-bootstrap', WDT_JS_PATH . 'bootstrap/noconf.bootstrap.min.js', array('jquery', 'wdt-bootstrap-select'), WDT_CURRENT_VERSION, true);        }

Now, I also noticed you have two drop-down arrows, and that shouldn't be the case - so even more proof that there's a conflict with the bootstrap files.

To fix this, please go to ../wp-content/plugins/wpdatatables/assets/css/bootstrap/wpdatatables.bootstrap.css and around line 4200, and change this:

.wpdt-c .caret {    display: inline-block;    width: 0;    height: 0;    margin-left: 2px;    vertical-align: middle;    border-top: 4px dashed;    border-top: 4px solid \9;    border-right: 4px solid transparent;    border-left: 4px solid transparent;
}

to this:

.wpdt-c .caret {    display: none;    width: 0;    height: 0;    margin-left: 2px;    vertical-align: middle;    border-top: 4px dashed;    border-top: 4px solid \9;    border-right: 4px solid transparent;    border-left: 4px solid transparent;
}

So, just change the display property to "none". All dropdowns should work, and you should have only one down arrow.

Please check and let me know if all's good.

You're welcome.

If you have any further questions or issues, please feel free to open a new ticket, and we'll gladly help.