When you manually install a certificate on Avaya Workplace Client for iOS, Avaya Workplace Client stops working on the device if you upgrade iOS to 10.3 or later.
Cause
The certificate is not automatically trusted for SSL.
Solution
Procedure
To turn on SSL trust for a certificate, on your iOS device, go to Settings > General > About > Certificate Trust Settings.
In the Enable full trust for root certificates area, enable the trust for the certificate.
