Here is my code:

SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

CREATE OR ALTER FUNCTION [dbo].[FormatExtractNumber]
    (@RawValue sql_variant)
RETURNS nvarchar(50)
AS
BEGIN
    DECLARE @FormatExtractNumber nvarchar(50)
    
    IF (SQL_VARIANT_PROPERTY(@RawValue,'scale') = 0 or @RawValue > 100000000000000000000000000000)
    BEGIN
        SET @FormatExtractNumber = CONVERT(nvarchar(50),@RawValue) 
    END
    ELSE
    BEGIN
        DECLARE @Raw_dec dec(38,7)

        SET @FormatExtractNumber = CONVERT(nvarchar(50), @Raw_dec)
        SET @FormatExtractNumber = CASE WHEN @Raw_dec = 0 THEN N'0' ELSE CASE WHEN  CHARINDEX('.',@FormatExtractNumber) > 0 THEN TRIM(TRAILING '0' FROM @FormatExtractNumber) ELSE @FormatExtractNumber END END
    END

    IF CHARINDEX(N'.',REVERSE(@FormatExtractNumber)) = 1
    BEGIN
        SET @FormatExtractNumber = REPLACE(@FormatExtractNumber, '.', '')
    END

    RETURN @FormatExtractNumber
END

I am getting the following error and I don't know why:

Msg 102, Level 15, State 1, Procedure FormatExtractNumber, Line 72 [Batch Start Line 9]
Incorrect syntax near '0'.

Msg 156, Level 15, State 1, Procedure FormatExtractNumber, Line 80 [Batch Start Line 9]
Incorrect syntax near the keyword 'END'.

Msg 102, Level 15, State 1, Procedure FormatExtractNumber, Line 83 [Batch Start Line 9]
Incorrect syntax near 'END'

I have isolated the problem to the following line as, when I comment this part, I can get the function installed:

SET @FormatExtractNumber = CASE WHEN @Raw_dec = 0 THEN N'0' ELSE CASE WHEN  CHARINDEX('.',@FormatExtractNumber) > 0 THEN TRIM(TRAILING '0' FROM @FormatExtractNumber) ELSE @FormatExtractNumber END END