I am using pgAdmin 4 1.0-beta1 (downloaded from pgadmin.org) on Windows 7.
When I try to SELECT a bytea column, like in the following:
SELECT decode('mama', 'escape');
I get a message like this:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
<title>500 Internal Server Error</title>
<h1>Internal Server Error</h1>
<p>The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.</p>
Yours,
Laurenz Albe