Compilation Failed Errors

I can’t get this plugin to work. I copied this line from the documentation but get an error:
[rdp-wiki-embed url=’https://en.wikipedia.org/wiki/United_States_Congress’%5D
Here is the error (this is repeated many times):
Warning: preg_match(): Compilation failed: invalid range in character class at offset 4 in /…/wp-content/plugins/rdp-wiki-embed/bl/simple_html_dom.php on line 1386

Maybe I just need to find a website where this plugin is being used properly to embed a wikipedia article. Then I can just copy the working line of code.