Numeric Field Issue

Numeric Field Issue

Hi

We are trying to import deals but hitting a roadblock every time. If I create a single line field, the data imports fine for this field (it's a currency field in csv). I have found I can't sum this field though when trying to do a revenue report. When I try to import as either a currency, number or decimal field, I constantly get this error.

Can anyone advise how we can get around this or get it to work?
Thanks