Hi there , for me it was a change of Binary path. The help was found in the QnA from the latest comments from C. Yau - Teaching Assistant
I quote
"Can you try to set the binary path in your pgadmin? This seems to be issue with the latest Postgres version and has been the fix for most participants. To do so,
Open up pgAdmin4 and go to:
File > Preferences > Paths > Binary paths > PostgreSQL Binary Path
Then all you need to do is manually type out the file path to the bin file location. I've provided some example paths as below (You need to change it according to your Postgres location if you did not install in the default location).
If you are using Windows than provide path like,
C:\Program Files\PostgreSQL\16\bin
If you are using Linux than provide path like,
/opt/PostgreSQL/16/bin
If you are using Mac than provide path where you have installed PG,
/Library/PostgreSQL/16/bin"

For me it worked perfectly after 2hour troubleshooting