Support has received several incidents related to the following Salesforce error:

login Failed 
UNSUPPORTED_CLIENT 
UNSUPPORTED_CLIENT: TLS 1.0 has been disabled in this organization. Please use TLS 1.1 or higher when connecting to Salesforce using https.

The error is generated because a critical update that enables support for TLS 1.1 has been activated in the Salesforce environment.

While it is tempting to apply the TLS update immediately, it is not mandatory for a few months as noted in the following Salesforce article:  Salesforce Disabling TLS 1.0.

Activating TLS 1.1 or higher before installing version 7.9.2 of TIBCO Scribe® Insight where Scribe has implemented the changes to support the new TLS version, introduces the errors shown above.  It is highly recommended that you deactivate this critical update until you upgrade TIBCO Scribe® Insight.

A Salesforce administrator can deactivate this update.  Contact Support if you need assistance with this.

NOTE:  Defect 25995 was discovered after the release of Insight 7.9.2 and was fixed by a hot fix. If you install Insight 7.9.2 and encounter the issue described below, see TIBCO Scribe® Insight V7.9.2 TLS/SSL Error to download and install this hot fix per the instructions in the .zip file. 

• Description: This hot fix resolves the issue of not being able to connect to a system because of a TLS/SSL error.
• Symptoms: When setting up a connection and clicking OK, you receive the following error:

• Cause: TIBCO Scribe® Insight was requiring TLS 1.2 to be enabled. On systems where TLS 1.2 is not enabled, Insight was not falling back to use TLS 1.1 or 1.0.

TLS versions supported by Scribe Insight and Insight Adapters