Dear Sir/ Ma'am,
Please apply the below steps for this issue.
1. Use the updated ERA explorer.
Link – alcera.mkcl.org
2. Disable antivirus and firewall
3. Disable IPV6 version
4. Clear browser cache.
(Press windows+ R, press %appdata%, press enter and delete the ERA explorer folder. Press windows+ R, press %temp% and delete the all cache)
Login the learner and check. Issue will get solve.
If the issue is not resolved, please generate the SOLAR ticket.