Access Keys:
Skip to content (Access Key - 0)

Q: Certificate Not Valid Error - Certificate Test Fails


  • Running Avast anti-virus/security software
  • Obtained certificate manually or with Certaid with no error messages/obvious issues
  • Certificate Test fails
  • Certificate not valid error

Avast software (provided by some vendors with new hardware as well as for stand-alone purchase) can cause MIT Certificates to silently fail when being installed due to how Avast secures your local keychain (identity data storage) information.


  1. Turn off or uninstall Avast.
  2. Obtain certificates. IS&T strongly recommends using Certaid.
  3. Install Sophos Anti-Virus or turn back on Avast to protect your computer.
IS&T Strongly recommends uninstalling any vendor-provided or third party security/anti-virus software and installing Sophos Anti-Virus. It is FREE to the MIT Community and has been tested with with MIT licensed software and services.

See Also

IS&T Contributions

Documentation and information provided by IS&T staff members

Last Modified:

August 03, 2020

Get Help

Request help
from the Help Desk
Report a security incident
to the Security Team
avast avast Delete
certaid certaid Delete
certificate certificate Delete
error error Delete
not not Delete
valid valid Delete
troubleshooting troubleshooting Delete
issue issue Delete
broken broken Delete
cert cert Delete
certs certs Delete
certificates certificates Delete
c-cert-troubleshooting c-cert-troubleshooting Delete
Enter labels to add to this page:
Please wait 
Looking for a label? Just start typing.
This product/service is:
Easy to use
Difficult to use

This article is:
Adaptavist Theme Builder (4.2.3) Powered by Atlassian Confluence 3.5.13, the Enterprise Wiki