Cannot install Password Manager certificate in Firefox

After installing Trend Micro Password Manager and add its extensions in Mozilla Firefox, you cannot install its certificate.

Why did this happen?

Password Manager extension is having compatibility issues with Mozilla Firefox when Primary Password is enabled.

What should I do next?

Disable Firefox Master Password:

1. Open Mozilla Firefox.
2. Go to Menu , then choose Options.
3. Select Privacy & Security, then scroll down to Logins and Passwords.
4. Uncheck Use a Primary Password.
5. Restart Mozilla Firefox.
6. Go back to Privacy & Security, then scroll down to Certificates.
7. Click the View Certificates button, then look for Password Manager Certificate.
8. Click Delete or Distrust, then choose Delete.
9. Close Mozilla Firefox, then wait for one minute for Password Manager to re-inject its Firefox Certificate.