Unable to access Twitter in the Chrome-Twitter and Public Information web application templates

Description

Users are unable to use the Twitter functionality of the Public Information and Chrome-Twitter Configurable Apps templates, both of which serve as a social media platform for users to share web maps and display geolocated tweets.
In some cases, the Twitter icon is disabled or missing. In other cases, users are unable to log in to Twitter.

Note:
While the Public Information template is still in use in ArcGIS 10.8 and other recent versions, as well as ArcGIS Online, the Chrome-Twitter template was only available through 10.3.

Cause

There are several possible reasons for this issue:

• Cookies are not enabled in the web browser, thus hindering the web application templates from storing Twitter OAuth application keys.
• Secured web map services are used.
• A Secure Sockets Layer (SSL) is enabled for the organization.
• The option to share content outside the organization is disabled in the security settings of the organization.
• A firewall or proxy server setting is preventing connection.

Solution or Workaround

Below are several options to resolve this issue.

• Configure the browser to allow cookies from arcgis.com, esri.com, or related Esri sites. 
• If using secured web maps, set the referrer URLs or IP addresses in ArcGIS Online. For more information, refer to ArcGIS Online: ArcGIS Server web services.
• Disable SSL for the organization. Refer to ArcGIS Online: Configure security settings for instructions.
• Enable sharing of content outside the organization by navigating to My Organization > Edit Settings > Security > Sharing and Searching. Check the checkbox next to the Members can share content outside the organization option.
• Configure the firewall or the proxy server settings to allow an ArcGIS Online connection with Twitter. Add arcgis.com, arcgisonline.com, esri.com, or related Esri domains to the firewall allowed list.