Below are the 2 kinds of issues you might face while uploading database :


1) Invalid Placeholder
This is to inform you that, you will get INVALID PLACEHOLDER error when your uploaded file has columns without header or if the file has junk character in header (junk character might come when we copy data from somewhere).
Usually, we have seen such entries are present in last column of the file. We request you to copy only required rows and column and paste into new CSV then upload new CSV on panel.
While copying don't use CTRL+A(copy all) instead copy only the required data.


2) Invalid Primary Key
Possibilities for Invalid Primary Key : 
1) Junk character in the file{Copy only required rows and column and paste into new CSV then upload new CSV on panel. While copying don't use CTRL+A(copy all) instead copy only the required data}
2) Your panel's primary key must not be in first column while uploading the data. It should be in the first column of csv file.
3) If the Header is missing