An issue has been identified affecting EU Cloud Partners, where the Wise-Sync application returns 503 - Service Unavailable.

Resolved: Thursday, 2 November 2017 at UTC11:15:00 am - ConnectWise have confirmed that the issue is now resolved.  

Update: Thursday, 2 November 2017 at UTC10:37:06 am - ConnectWise have confirmed that there are known issues with their API. They are actively investigating.

ConnectWise Platform Ticket:
Ticket# 9534467> URGENT - Unable to connect to EU Cloud Instance (Version Router returning 503 Service Unavailable)

A temporary work around can be set to allow partners to continue to sync: 

1. Log into Wise-Sync via a browser -
2. Click on Account
3. On the Account Details Tab, update the "ConnectWise: PSA Dir: to "v2017_6"
4. Click Test ConnectWise Connectivity
5. Click Save.

Please note that these settings will need to be reverted once the issue has been resolved.