Please check the network port is open from that client. dose other user are able to access EBS?
how to check the network ports if blocked or not?
Update the s_frmNetworkRetries context variable to a larger - typically 25 or 30 - then run autoconfig.
Not enough details in your post.
Application release? DB version?
Is the issue with all forms?
Does the issue happen to all users?
Was this working before? If so, any changes were made recently?
Were the services bounced?
Any errors in application/database logs?
Was AutoConfig run with no issues?