Problem with month to month calculation quick formula Error message

Mstrande , Not sure I am clear with your issue. But make sure you have created a date table and join it with your date in your transaction table

To get the best of the time intelligence function. Make sure you have a date calendar and it has been marked as the date in model view. Also, join it with the date column of your fact/s. Refer :
https://radacad.com/creating-calendar-table-in-power-bi-using-dax-functions
https://www.archerpoint.com/blog/Posts/creating-date-table-power-bi
https://www.sqlbi.com/articles/creating-a-simple-date-table-in-dax/

See if my webinar on Time Intelligence can help: https://community.powerbi.com/t5/Webinars-and-Video-Gallery/PowerBI-Time-Intelligence-Calendar-WTD-YTD-LYTD-Week-Over-Week/m-p/1051626#M184


Appreciate your Kudos.

Hi Mstrande ,

You could create a rank column based on your date column at first. Then refer to the following measure to get the result.

Column 2 =
VAR a =
    CALCULATE (
        FIRSTNONBLANK ( 'Table'[MSEK], 1 ),
        FILTER (
            'Table',
            'Table'[rank]
                = EARLIER ( 'Table'[rank] ) - 1
                && 'Table'[Project] = EARLIER ( 'Table'[Project] )
        )
    )
RETURN
    'Table'[MSEK] - a

Here is my test file for your reference.