Each addon module has specific errors that you might encounter. Troubleshoot and resolve Client import failed errors while attempting to import data using the ImportAssist addon module. Troubleshoot and resolve connection errors that occur when WHMCS Cloud cannot reach an external source database during an ImportAssist migration. Troubleshoot and resolve validation failures while importing data using the ImportAssist addon module. Troubleshoot and resolve Unable to Connect errors while using the ImportAssist addon module. Troubleshoot and resolve missing or duplicate clients after importing data using the ImportAssist addon module. You can use automated options like Sync Accounts or Importassist help you migrate client data, hosting accounts, and domains from other billing systems to WHMCS using automated import tools, or you can add data using manual entry. ImportAssist migrates data from external systems into WHMCS. It can import data from other WHMCS instances, other applications, or CSV import files.