Invalid argument(s) (onError): The error handler of Future.catchError must return a value of the future's type

ClientException: Bad file descriptor, uri=https://etifaq.app/api/contracts/2507

ClientException: Connection reset by peer, uri=https://etifaq.app/api/contracts/?status=all&bureau=4

ClientException: Connection closed while receiving data, uri=http://159.223.19.166:3006/technical/conversations/449

type 'Null' is not a subtype of type 'String'

ClientException: Bad file descriptor, uri=http://159.223.19.166:3006/person_conversation_id/754

ClientException with SocketException: Operation timed out (OS Error: Operation timed out, errno = 60), address = 159.223.19.166, port = 51233, uri=http://159.223.19.166:3006/unseenMessages/1120

ClientException with SocketException: Failed host lookup: 'etifaq.app' (OS Error: nodename nor servname provided, or not known, errno = 8), uri=https://etifaq.app/api/contracts/?status=all&bureau=4&search=3138

ClientException: Bad file descriptor, uri=https://etifaq.app/api/contracts/?status=unverified&bureau=4

ClientException with SocketException: Bad file descriptor (OS Error: Bad file descriptor, errno = 9), address = 159.223.19.166, port = 51862, uri=http://159.223.19.166:3006/unseenMessages/778

ClientException with SocketException: Bad file descriptor (OS Error: Bad file descriptor, errno = 9), address = 159.223.19.166, port = 59406, uri=http://159.223.19.166:3006/unseenMessages/535

ClientException with SocketException: Bad file descriptor (OS Error: Bad file descriptor, errno = 9), address = 159.223.19.166, port = 59405, uri=http://159.223.19.166:3006/unseenMessages/535

ClientException with SocketException: Bad file descriptor (OS Error: Bad file descriptor, errno = 9), address = 159.223.19.166, port = 59404, uri=http://159.223.19.166:3006/unseenMessages/535

ClientException: Bad file descriptor, uri=http://159.223.19.166:3006/technical/conversations/616

ClientException: Bad file descriptor, uri=http://159.223.19.166:3006/unseenMessages/197

ClientException: Connection closed while receiving data, uri=http://159.223.19.166:3006/technical/conversations/750

ClientException: Bad file descriptor, uri=http://159.223.19.166:3006/unseenMessages/750

ClientException with SocketException: Bad file descriptor (OS Error: Bad file descriptor, errno = 9), address = 159.223.19.166, port = 49977, uri=http://159.223.19.166:3006/unseenMessages/750

ClientException with SocketException: Write failed (OS Error: Broken pipe, errno = 32), address = 159.223.19.166, port = 49987, uri=http://159.223.19.166:3006/unseenMessages/750

ClientException: Connection closed while receiving data, uri=http://159.223.19.166:3006/technical/conversations/294