SLICERS -> blank value

I don’t think this is a bug. The reason you may think this is a bug is because the "Slicer" treats "Blanks" different to other visuals. Try the following to see if you have the same issue as I did and then how you can fix it

Issue:

Fact Table

[Column 1]      

a1

a2

a3

Data Table

[Column 1]      [Column 2]    [Column 3]

a1                     b1                   100

a2                     b2                   200

                         b3                   300

Relationship 

Fact Table [Column 1] >> Data Table[Column 1]

Bring [Column 1] from Fact Table into slicer

Bring [Column 1] from Fact Table into table

You will see [Blank] in the Slicer although you don't have any blank in this column in the fact table. But, when you bring the same field in the a table visual you don't see the blank. The table visual doesn't show the blank because a table visual (or any other visual) will remove the row if all the values in that row is blank. 

The reason for you see Blank in the slicer is because the Data Table has a "blank" value in [Column 1]. 

If you bring [Column 1] from the Data table in the "Table" visual, you will not see the blank. This is because the "table" will automatically remove the blanks. Bring in another [Column 2] from Data table in the "table" visual and you can now see the blank.

HOW TO FIX THIS

Create a table from the Data table, bring in the column causing you this issue and another column (both from the Data table) without summarizing any of the field (i..e don't add or count any of the field). You will see the row with the blank field. 

Thanks

Nishant