502 Bad gateway (no replies)

Good morning!

I'm working on a project and we are facing issues trying to get the views on the products using the method 'getItemsSku' with a pattern.

Here is the link:
https://piwik.teachwise.com/index.php?&period=range&date=2014-09-17,2015-01-14&idSite=1&token_auth=bc61f99150796266ce4dadd0581d7454&format=json&filter_limit=-1&module=API&method=Goals.getItemsSku&filter_pattern=C0000693-4250-AAM-GPK%7CC0000693-4249-AAM-G04

why could this be happening?

Thanks in advance.