The following bug has been logged on the website:
Bug reference: 15011
Logged by: Carlos Florentino
Email address: c18florentino@yahoo.com
PostgreSQL version: 9.6.4
Operating system: W10 - 1709 x86
Description:
"The application server could not be contacted!"
pgAdmin 4.2.1
Local machine
Server is runnig ok (front end LO Base)
I've found this workaround in SatckOverflow: deleting all entries in
directory
...\AppData\Roaming\pgAdmin\sessions
This works...
Thank you in advance.