Ran the example from https://anyquery.dev/query/what_s_the_pid_of_a_process/ via:

anyquery run what_s_the_pid_of_a_process

And after inserting "python" and pressing RET in the TUI input field, I see:

could not request the rows from the plugin
unexpected EOF

This is on Windows 10, anyquery 0.4.4 installed via Scoop (https://anyquery.dev/docs#windows-scoop).