Why "\ d + {1,4} (?: [.,] \ D {1,4})?" in RegularExpressionValidator throws Exception: "Nested quantifier {"

I have

<asp:RegularExpressionValidator ValidationExpression="\d+{1,4}(?:[.,]\d{1,4})?" />

      

        
        
        
      

    

but it doesn't work, the parser throws an ArgumentException:

parsing "\ d + {1,4} (?: [.,] \ d {1,4})?"

Nested quantifier {.

Where is my mistake? I want to allow the type of line xxxx,xxxx

- from 1 to 4 digits and decimal digits are required, such as 1000

, 99,99

, 0,2498

, etc.