Trigger to insert new row into second table causes “Connection is busy with results for another command”

Question

I have created this trigger to insert new row into table @AL_ORDR_TRACKER after new row is inserted in table ORDR.

CREATE TRIGGER dbo.trgAfterInsertORDR ON dbo.ORDR
AFTER INSERT
AS
BEGIN
INSERT INTO dbo."@AL_ORDR_TRACKER"
        (U_DocEntry, U_Updated)
    SELECT
        DocEntry as U_DocEntry, GETDATE() U_Updated
        FROM inserted
END

The trigger gets registered but when inserting new rows into ORDR I get the error message:

Connection is busy with results fro another commands

What might be going wrong here?