Solution:
Step1: Log out the learner.
Step2: Disable the firewall/antivirus as well as IPv6 (IPv6 is present in Open network and internet setting option).
Step3: Do cache clear of ERA folders and system files. With following steps (press windows + R, enter %appdata%, and delete or rename the ERA explorer folder)
Step4: Do LF Login and perform a health check more than two times.
Step5: Do the learner login and your issue will get solved.
If issue persists, please generate the SOLAR ticket with following details.
Learner Code-(those are facing issue)
Screen shot of the issue-
Detail description.
Updated mobile number.