Recently I installed Magento 2.1.3. The problem is that, when i am in the Component Maganer, and i Sync my account, it showns an infinite “please wait” loading, and i can’t install any extension at all.

After some research and searching I found one solution as below.

Please open your composer.json file and move to “repositories” section, and left only one repository, like shown below.

Before:

After:

Modifying “repositories” in composer.json fixed this issue for me.