Error: 504 or Load Failed connecting to your ERP

Created by Damien Zwillinger, Modified on Fri, 10 Nov, 2023 at 1:19 PM by Harry Lewis

Applies to:

  • Velixo NX
  • Every ERP


While configuring a connection to your ERP, the Velixo NX Connection Manager displays either a 504 message:


or a Load Failed message:




Important site accessibility & firewall considerations

Modern Excel add-ins cannot make a direct connection to your ERP system due to the browser engine restrictions for cross-origin requests.  In Excel for Mac and Excel Desktop for Windows, MS Office utilizes a Safari or Edge-based browser engine behind the scenes.


Therefore, Velixo NX uses a secure proxy server to facilitate the connection to your ERP system.   The proxy never caches or stores your ERP data, it is used solely for authentication and request pass-through. 


However, the fact that such a proxy server exists has two important implications:

  • Any ERP site that you connect to must be accessible over the public internet, with no VPN requirement

  • If your ERP host uses a firewall, it is important to allow-list not just your end users' IP addresses, but also those of Velixo NX's proxy servers.  More information can be found in Understanding external server connections.

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