deliot

Try one of the WordPress default themes (2012, 2013) temporarily, and see if it works with that. If it does, then it may be your theme.

My server is running Ubuntu 12.04 with PHP 5.4.17, and there are no problems with this plugin. Worked perfectly out of the box.

If you happen to be using the Semiologic CMS WordPress theme, then it’s the theme itself that has the problem. Read this post at the Semiologic forum:

https://forum.semiologic.com/discussion/1928/error-message-using-print-link/#Item_0

Another way to make “Open Link in a NEW Window” the default is to edit the line:

from:
<option value="_blank">

to:
<option value="_blank" selected="selected">

So “_blank” now becomes the SELECTED default for the drop down list. Same as what aar0on said, only without changing the order of the options.

Actually, you should add selected=”selected” This will be better for XHTML compliance, as in XHTML, all attributes must be quoted. See here for a discussion of this:
https://www.w3schools.com/xhtml/xhtml_syntax.asp

Here’s how it should be:
<option value="_blank" selected="selected">{$lang_insert_link_target_blank}</option>