In VIEWER, Cannot print a SELECTED portion

In the VIEWER pane, I need to print a portion of a text file. I Select the portion, right click, Print, but the Selection button is grayed out.
Can this be enabled ?

You mean this (see screenshot below)? I'm not sure, but I don't think it can be done and I don't know if it's a bug ...
But you could Select the text > Right-Click in the viewer pane and choose Copy > Activate the main file display and Ctrl-V Paste > Print the new text file.