strange problem - date format is no longer being recognized because of "/" in my formula

[Denskim123]

Hi community,

I'm encountering a strange problem that I have not encountered before. I created a new measure/column using the formula shown below combining the 2 columns 'Month1' and 'Year1' to get the column 'MO/YR'. I also set this column format to be a date and it has been working great. 

Today, after refreshing my data (as I typically do), all of a sudden PowerBI is no longer recognizing that column as a date format and is throwing this error message. I can't figure out why all of a sudden it's saying the "/" is an issue???

Does anyone know why this might be happening and what/how I can correct it?  Thanks a million.

[HotChilli · Accepted solution]

I think, like Greg, we have to hypothesise that the new data is causing a problem.
Are the Year1 and Month1 columns number type?

Why don't you comment out the code and put this in the calculated column:

DATE ( 'Raw Data'[Year1], 'Raw Data'[Month1], 1 )

The way it's currently written involves some conversions behind-the-scenes which may be prone to error.

This new code might throw an error but it may allow you to narrow it down.

[Denskim123]

@HotChilli your suggestion worked great! i went back and double checked my columns but didn't find anything out of place. i'm still baffled. in anycase, thanks for your alternative solution!

[Greg_Deckler]

@Denskim123 My guess is that you literally have a "/" in your data for some reason as if your Year1 and Month1 columns for a particular row are null.

[Denskim123]

I checked my columns for a null value or to see if any cell contained "/" but nothing. columsn are clean and only has the values that I expect to see. I'm totally baffled as to why this is happening all of a sudden....