Connector can't commit chager

I have a problem.
When import/update rows with printers attributes eg. custodian (domain/username) connector display that all is ok - realationship created, but at the end it get an error and can't commit changes
For small group of record it works fine. What to change/check?
2022/02/02 13:11:33.915 - Created System.ConfigItemOwnedByUser relationship for "Samsung SL-M2022W (0031960)" to "Dominik Olczyk" 2022/02/02 13:11:33.917 - Updated Cireson.AssetManagement.HardwareAsset "Samsung SL-M2022W (0031960)" 2022/02/02 13:12:29.417 - Error - could not commit current batch - The client has been disconnected from the server. Please call ManagementGroup.Reconnect() to reestablish the connection. 2022/02/02 13:12:29.425 - Error - The client has been disconnected from the server. Please call ManagementGroup.Reconnect() to reestablish the connection. 2022/02/02 13:12:29.442 - Error - The client has been disconnected from the server. Please call ManagementGroup.Reconnect() to reestablish the connection. 2022/02/02 13:12:29.444 - Error - Object reference not set to an instance of an object. (current property="", current value="")
Answers
continue in https://community.cireson.com/discussion/5522/sync-hardware-assets-failing#Item_3