I’m having this same exact issue. I’m using WordPress version 5.0.2 and WooCommerce version 3.5.3.
Every time I activate WooCommerce I get the same error:
“The server is temporarily unable to service your request due to maintenance downtime or capacity problems. Please try again later.
Additionally, a 503 Service Unavailable error was encountered while trying to use an ErrorDocument to handle the request.”
When I deactivate WooCommerce, the site is back up.
Is this a known issue, and is there a solution?
Thanks!