Since 4.7.13 on Wordpress I am unable to upgrade my CiviCRM install. I enclose an image of the error message I get.
Clicking on the Retry or the Skip buttons has no effect.
I can't see what's going wrong, as I've not had any problems before. I am running WordPress 4.7.2, have no extensions, and cleared the cache and template_c folder as instructed on this page