Number of referencing columns in foreign key differs from number of referenced columns, table 'TableName'.

When creating/adding referential integrity constraints on a Table, The following error occurred in various scenarios as given below..

Number of referencing columns in foreign key differs from number of referenced columns, table 'TableName'.

Meaning:
Column name not specified for the foreign key constraints.

When creating table:
IF OBJECT_ID('Tb_Table2','U') IS NULL
CREATE TABLE Tb_Table2
(
Id INT,
Column2 VARCHAR(10),
CONSTRAINT FK_ID FOREIGN KEY REFERENCES Tb_Table1(Id)
)
GO

or

Adding foreign key constraint on existing table:
ALTER TABLE Tb_Table2 ADD CONSTRAINT FK_ID FOREIGN KEY REFERENCES Tb_Table1(Id)
GO

Column name not specified for Foreign key constraints in both scripts

The script should be as follows...

IF OBJECT_ID('Tb_Table2','U') IS NULL
CREATE TABLE Tb_Table2
(
Id INT,
Column2 VARCHAR(10),
CONSTRAINT FK_ID FOREIGN KEY(Id) REFERENCES Tb_Table1(Id)
)
GO

or

ALTER TABLE Tb_Table2 ADD CONSTRAINT FK_ID FOREIGN KEY(Id) REFERENCES Tb_Table1(Id)
GO

Here, Id is the Parent table Key column.