The application server could not be contacted

[Carl Rylett]

Hi, I have just downloaded Postgresql v11.1. and pgAdmin4 3.4  from 
postgresql.org for Windows 10.I get an error message when starting pgAdmin 'The 
application server could not be contacted'After searching around I find I can 
get round by running as administrator and deleting the contents of 
AppData/Roaming/pgAdmin but have to so this every time I start pgAdmin. Any 
suggestions please how I can get round this?
Thanks,Carl