You didn't give enough information about the structure of your form & list.
If I change a column from a String to a Currency, I get the same error onload of my form. That is whether I am filling in the field like this:
txtMyFirstField.Text+txtMySecondField.Text+txtMyThirdField.Text
or like this:
If(IsBlank(txtMyFirstField.Text+txtMySecondField.Text+txtMyThirdField.Text),
0,
txtMyFirstField.Text+txtMySecondField.Text+txtMyThirdField.Text
)
or this:
If(IsBlank(Value(txtMyFirstField.Text)+Value(txtMySecondField.Text)+Value(txtMyThirdField.Text)),
0,
Value(txtMyFirstField.Text)+Value(txtMySecondField.Text)+Value(txtMyThirdField.Text)
)
(You'd think with them all being the same type, no issue, right? HA.)
What I had to do instead was:
1. Change my Currency field where totals were going to into a String field type on the list, instead
2. Update that same field in my Power Apps form to have a Format = Text
3. Used this in my Default:
Text(txtMyFirstField.Text+txtMySecondField.Text+txtMyThirdField.Text,"[$-en-US],$##,###.00")
So it will just get set as a currency format from the value in the field, on save, from the form, itself.
I'm thinking this HAS to be a bug within Power Apps, that we have to set the field as a String field on the list and can't write a number to a Currency field. Especially when I'm doing exactly this from user-input directly into the 3 fields I'm specifying ("My First Field", "My Second Field", "My Third Field") that are all Currency fields and take values from the user just fine. Utterly ridiculous!
