How to check for proxy settings in a server

1. Windows Server 2003 and before:

Open a Command Prompt window and type :

 proxycfg

2. After Windows Server 2003:

Open a Command Prompt window and type :

netsh winhttp show proxy

SharePoint 2013 People Picker error: “Sorry, we’re having trouble reaching the server"

Issue Description

I was working on a SharePoint 2013 site and trying to add some users and got the below error

I tried adding the same user on other site collections but same error.

Also checked the Event Logs but couldn’t find anything useful

Fix

I did an IISRESET and this fixed the issue

Difference between Service Packs , Cumulative updates, Public Updates and Security Updates

Service Pack

A tested, cumulative set of all hotfixes, security updates, critical updates, and updates. Additionally, service packs may contain additional fixes for problems that are found internally since the release of the product. Service packs my also contain a limited number of customer-requested design changes or features.

What is included: new fixes, new functionality, all previously released fixes (older Service Packs, CUs, PUs)

Cumulative Update (CU)

A Cumulative Update includes fixes for problems with our product that have been reported by customer in context of support cases.

What is included: new and all previously released fixes (CUs and PUs) since the oldest supported service pack (within the first 12 month after a Service Pack has been released the CU includes also fixes released after the previous service pack)

Public Update (PU)

A Public Update usually includes security fixes for the product or fixes for problems which affect a broad number of customers.

What is included: Review the KB article for each public update in detail to see which fixes are included.

Security Update

A widely released fix for a product-specific, security-related vulnerability. Security vulnerabilities are rated by their severity. The severity rating is indicated in the Microsoft security bulletin as critical, important, moderate, or low.

References : 1, 2