2669121 - Failed to call remote system on /service/api/epm/proxy by Agent HCPService; Reason: creation of UTF16 string failed in SAP Analytics Cloud (SAC)

The following error occurs when trying to import a BPC model in SAP Analytics Cloud (SAC) and the import hangs (...):

• {"message":"Failed to call remote system on /service/api/epm/proxy by Agent HCPService; Reason: creation of UTF16 string failed","stack":"","errorDetails":[{"messageId":"CALL_REMOTE_SYSTEM_FAILED","message":"Failed to call remote system on /service/api/epm/proxy by Agent HCPService; Reason: creation of UTF16 string failed","bUIMessage":false,"bWarning":false}],"status":500,"bUIMsg":false,"bWarning":false}

• SAP Analytics Cloud 2018.11.3

SAP Cloud for Planning, sc4p, c4p, cforp, cloudforplanning, EPM-ODS, Cloud for Analytics, Cloud4Analytics, CloudforAnalytics, Cloud 4 Planning, BOC, SAPBusinessObjectsCloud, BusinessObjectsCloud, BOBJcloud, BOCloud., SAC, SAP AC, Cloud-Analytics, CloudAnalytics, SAPCloudAnalytics , KBA , LOD-ANA , SAP Analytics Cloud (SAC) , LOD-ANA-BI , Business Intelligence Functionality, Analytic Models , LOD-ANA-PL , Planning , LOD-ANA-BR , SAC Boardroom , LOD-ANA-PR , SAC Predictive , Problem