3622535 - SAP B1 Connector Error: "Input String Was Not in a Correct Format"

The FSM B1 Cloud Connector throws the following error when an Activity is checked out and closed:

• Input string was not in a correct format.

ERROR|2025-06-04 14:55:32.6387
ObjectWriter.SaveXml error
SAPB1Connector.DI.ObjectWriter.SaveXml System.FormatException: Input string was not in a correct format.
   at System.Number.StringToNumber(String str, NumberStyles options, NumberBuffer& number, NumberFormatInfo info, Boolean parseDecimal)
   at System.Number.ParseInt32(String s, NumberStyles style, NumberFormatInfo info)
   at SAPB1Connector.DI.Writers.Activity.ActivityWriter.SetFields(IContacts activity, XmlDocument doc)
   at SAPB1Connector.DI.Writers.Infrastructure.DiObjectWriter`1.Write(XmlBasedDownstreamEvent xmlBasedDownstreamEvent)
   at System.Threading.Tasks.Task`1.InnerInvoke()
   at System.Threading.Tasks.Task.Execute()ERROR|2025-06-04 14:55:32.6507

Could not save object to SAP B1.
ObjectType: ACTIVITY
TransactionId: 2833
GUID: 956E2E28762D4FA9936F8FBF3C62421D
Message: One or more errors occurred.
Error: System.AggregateException: One or more errors occurred. ---> System.FormatException: Input string was not in a correct format.
   at System.Number.StringToNumber(String str, NumberStyles options, NumberBuffer& number, NumberFormatInfo info, Boolean parseDecimal)
   at System.Number.ParseInt32(String s, NumberStyles style, NumberFormatInfo info)
   at SAPB1Connector.DI.Writers.Activity.ActivityWriter.SetFields(IContacts activity, XmlDocument doc)
   at SAPB1Connector.DI.Writers.Infrastructure.DiObjectWriter`1.Write(XmlBasedDownstreamEvent xmlBasedDownstreamEvent)
   at System.Threading.Tasks.Task`1.InnerInvoke()
   at System.Threading.Tasks.Task.Execute()

• SAP Field Service Management (FSM)
• SAP Business One (SAP B1)

input string, incorrect format, ERP, save records, add records, connector queue, SAP B1, activity, corrupt, blocked status, FSM, Business One, 8.5.1 , KBA , CEC-SRV-FSM-BOC , FSM Business One Connector , Known Error