Warning: preg_match(): Compilation failed: two named subpatterns have the same name at offset 75

I was using the ARVE video embedder plugin on WordPress.

Observing a page referencing either Vimeo or YouTube I saw the error:

Warning: preg_match(): Compilation failed: two named subpatterns have the same name at offset 75 in /wp-content/plugins/advanced-responsive-video-embedder/public/functions-shortcode-filters.php on line 255 

Disabling plugins didn’t cure the issue

And reverting to the default TwentySeventeen theme didn’t resolve the issue

I configured another website with the plugin with the aim of comparing the two websites. There was no error!

ARVE has a handy Debug Info tab on its settings page. I used this to compare the two websites.

Here’s the part of interest:

ARVE Version:      8.9.10
ARVE-Pro Version:  NOT INSTALLED
WordPress Version: 4.9.8
PHP Version:       5.6.38

The working website was running version 7 of PHP.

I switched the version on the erroring site to 7.0. The error message disappeared.