When i try to change settings, it goes blank, and nothing changes.

Version is 4 2 2 and theme is twenty sixteen.

No, one site use wpec, another site woocommerce. Other plugins no difference.
Plugins list:

Black Studio TinyMCE Widget
Atspējot | Labot
Adds a new “Visual Editor” widget type based on the native WordPress TinyMCE editor.

Versija 2.2.8 | Izstrādāja Black Studio | Apskatīt detaļas | Home | FAQ | Support | Rate | Follow | Donate
Atlasīt Cookie Law Info
Cookie Law Info
Atspējot | Labot | Settings | Beta 2.0
A simple way of ‘implied consent’ to show your website complies with the EU Cookie Law, which came into force on 26 May 2012.

Versija 1.5.3 | Izstrādāja Richard Ashby | Apskatīt detaļas
Atlasīt Disable Emojis
Disable Emojis
Atspējot | Labot
Disable Emojis

Versija 1.5.1 | Izstrādāja Ryan Hellyer | Apskatīt detaļas
Atlasīt Dynamic To Top
Dynamic To Top
Atspējot | Labot
Adds an automatic and dynamic “To Top” button to scroll long pages back to the top.

Versija 3.4.2 | Izstrādāja Matt Varone | Apskatīt detaļas
Atlasīt GD Rating System
GD Rating System
Atspējot | Labot
Powerful, highly customizable and versatile ratings plugin to allow your users to vote for anything you want.

Versija 1.1.1 | Izstrādāja Milan Petrovic | Apskatīt detaļas
Atlasīt Gold Cart for WP e-Commerce
Gold Cart for WP e-Commerce
Atspējot | Labot
Gold Cart extends your WP e-Commerce store by enabling additional features and functionality, including views, galleries, store search and payment gateways. See also: GetShopped.org | Premium Support | Documentation

Versija 2.9.7 | Izstrādāja GetShopped.org | Apmeklēt spraudņa vietni.
Atlasīt Google Analytics by Yoast
Google Analytics by Yoast
Settings | FAQ | Atspējot | Labot
This plugin makes it simple to add Google Analytics to your WordPress site, adding lots of features, e.g. error page, search result and automatic outgoing links and download tracking.

Versija 5.4.6 | Izstrādāja Team Yoast | Apskatīt detaļas
Atlasīt Google Sitemap by BestWebSoft
Google Sitemap by BestWebSoft
Aktivizēt | Labot | Dzēst
Plugin to add google sitemap file in Google Webmaster Tools account.

Versija 3.0.2 | Izstrādāja BestWebSoft | Apskatīt detaļas
Atlasīt Loginizer
Loginizer
Settings | Atspējot | Labot
Loginizer is a WordPress plugin which helps you fight against bruteforce attack by blocking login for the IP after it reaches maximum retries allowed. You can blacklist or whitelist IPs for login using Loginizer.

Versija 1.0.2 | Izstrādāja Raj Kothari | Apskatīt detaļas
Atlasīt Remove/hide Author, Date, Category Like Entry-Meta
Remove/hide Author, Date, Category Like Entry-Meta
Atspējot | Labot
This plugin Remove the Author, Date, Category, Comment and Edit links meta data under the each posts. If you want hide seleted one go to this plugin select checkboxes what you want hide or remove. By default this plugin remove the total meta.

Versija 1.0 | Izstrādāja Venugopal. | Apskatīt detaļas
Atlasīt WP eCommerce
WP eCommerce
Atspējot | Labot | Premium Support | Documentation
A plugin that provides a WordPress Shopping Cart. See also: WPeCommerce.org | Support Forum | Documentation

Versija 3.11.2 | Izstrādāja WP eCommerce | Apskatīt detaļas
Atlasīt WP Meta SEO
WP Meta SEO
Atspējot | Labot
WP Meta SEO is a plugin for WordPress to fill meta for content, images and main SEO info in a single view.

Versija 1.7.3 | Izstrādāja JoomUnited | Apskatīt detaļas
Atlasīt WP-SpamShield
WP-SpamShield
Settings | Atspējot | Labot

If i log to cpanel and check files, there is many old folders from old uninstalled plugins (but folders and files is still there), so i do not know, maybe one of this can gives any effect to how wordpress site works…

So dont worry, i think not your plugin alone is bad, WORDPRESS is bad! 🙂

I checked everything, and found this htacess file on that server, on which i cannot change settings. On other server i have not htacess at all.
What i remember, this file earlier looks much different.
Maybe on server side server admins make some tweaks.
But plugin works as advised, only i cannot change plugin settings.
Here is htacess. I do not know, it can helps you to make some thoughts or not, but here it is:

<IfModule mod_deflate.c>
SetOutputFilter DEFLATE
<IfModule mod_setenvif.c>
# Netscape 4.x has some problems…
BrowserMatch ^Mozilla/4 gzip-only-text/html

# Netscape 4.06-4.08 have some more problems
BrowserMatch ^Mozilla/4\.0[678] no-gzip

# MSIE masquerades as Netscape, but it is fine
# BrowserMatch \bMSIE !no-gzip !gzip-only-text/html

# NOTE: Due to a bug in mod_setenvif up to Apache 2.0.48
# the above regex won’t work. You can use the following
# workaround to get the desired effect:
BrowserMatch \bMSI[E] !no-gzip !gzip-only-text/html

# Don’t compress images
SetEnvIfNoCase Request_URI .(?:gif|jpe?g|png)$ no-gzip dont-vary
</IfModule>

<IfModule mod_headers.c>
# Make sure proxies don’t deliver the wrong content
Header append Vary User-Agent env=!dont-vary
</IfModule>
</IfModule>