Expression.Error: We cannot convert the value 31 to type Text.

I have merged many columns from different files from one folders together. The data of the column of #Days are in numbers and there's also "no offer" in the column. However, I am getting error for "DBS". It says "error" for the #Days for DBS. I am trying to get the numbers. 

Expression.Error: We cannot convert the value 31 to type Text.
Details:
Value=31
Type=[Type]

I can't get it to be transferred to numbers. I also have "no offer" in the original excel file. So, I don't know if that could've affected the "#Days" for DBS