On a Grid view (custom object or stock e.g. Risks / Tasks) - when you use the plus symbol (+) to create 2 or more blank rows then you use shift-click to select all required fields from the preceding row and use the drag copy/paste to copy the data from that row into the 2 (or more) blank rows.
The data is copied into the blank rows but multiple additional duplicate rows are also created.
STEPS TO REPRODUCE:
1. Enable auto-numbering for the ID of 'Risk' object
2. Go to 'Risks' list page and create an instance of Risk
3. Using the Plus symbol (+), create 2 blank rows
4. Use the shift-click to select all required fields from the preceding row (instance created in step 2) and use the drag copy/paste to copy the data from that row into the 2 blank rows. (Dragged the bottom right corner of the
selected cells up into the above 2 rows).
Data will be copied into the two rows only
Data gets copied into nineteen rows instead of only two
Logged as defect id: DE64930
Release : 16.0.1
Component : Clarity MUX UI Usability
Engineering has reviewed and determined that this is not a defect.
For inline create, we do not support bulk inserts in the grid - you can only create one record at a time.
Create Risk instance, one at a time
or Disable auto numbering of Risk object ID to prevents this behaviour from occurring