Get "not allowed for columns on the one side of a many-to-one relationship" errors

[JonAv]

I have a pbix file that successfully loaded data and everything worked.  The next day I tried refreshing it, and got this peculiar error:

Column ‘MAMUserPercent’ in Table ‘CapacityReport_ASUDeviceRatios’ contains a duplicate value ‘0.5’ and this is not allowed for columns on the one side of a many-to-one relationship or for columns that are used as the primary key of a table.

I could not find any reason for the error, either in the table itself or in any references to the table.  Since I was out of ideas, I duplicated the table, changed all references to the new copy, and deleted the old one, and the refresh then failed with a similar error but on a different table:

Column ‘Total Device Check-ins Per Day’ in Table ‘CapacityReport_MonthlyCapacity’ contains blank values and this is not allowed for columns on the one side of a many-to-one relationship or for columns that are used as the primary key of a table.

I repeated the process and the next refresh succeeded.  I'm worried that I will continue to hit this randomly when i refresh.  Any ideas on what's going on?

[detuniko]

I faced the exact same issue. And when I clicked "Manage Relationships" on the Home tab, I found that automatically two tables were joined, and it made no sense to join them both. Once I deleted the relationship, and published the changes, I was able to refresh the tables data!

[Swamy3105]

Super, it really worked for me. I had the same issue and i was struggling to get resolved this issue.

I had no idea what was the wrong in my table and all.

thanks for this!

[CahabaData]

take a look at relationships;  you may find join lines that shouldn't exist; this can occur in my experience if one is adding tables/columns and there is an identical column name - sometimes it seems a join line is made automatically....

the error messages definitely indicate inappropriate join lines;  the only join line should be between fundamental key fields