When I try to upgrade the plugin I get this:
Updating Plugin Event Organiser Pro (1/1)
Downloading update from https://event-organiser-pro.s3.amazonaws.com/event-organiser-pro.zip?AWSAccessKeyId=AKIAJ6B5OEIZEUPPEBAA&Signature=udXZkmQGkElUTGAy4ZaUxntZlYk%3D&Expires=1380729816&license=E26Y-X35Q-NSFK-AADW…
Warning: unlink(C:\Users\ADMINI~1\AppData\Local\Temp\2/event-organiser-pro19.tmp): Permission denied in C:\xampp\htdocs\gmesuu\wp-admin\includes\file.php on line 504
An error occurred while updating Event Organiser Pro: Download failed. SSL certificate problem, verify that the CA cert is OK. Details: error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed
The other plugins upgrade correctly.
Cheers

Ricardo Cifres
Hi Ricardo,
You’re getting this error because your host doesn’t recognise Amazon’s SSL ceritficate (this maybe because their records are outdated). You can work-around this by adding the following to your site’s utility plug-in, or theme’s functions.php
:
add_filter('https_ssl_verify', '__return_false');
add_filter('https_local_ssl_verify', '__return_false');
(To give you an idea of what this means: it disables ‘SSL verify’, which, when enabled means the plug-in attempts to verify that the source of the plug-in version being downloaded is what it says it is, and not an attacker intercepting the request and feeding you a version corrupted by malware. While this is not essential, its recommended, but if you’re host is unwilling to update their certificates this is the only way.)

Stephen Harris
Thanks Stephen, it worked fine. I will apply the work around only when needed.

Ricardo Cifres