Hi,
I am using SQL Dev 17.2 with JDK 8u72 on Windows.
There is something strange on Popup Describe - tab Details.
Here is the step to reproduce :
1. Open pop up describe

2. Open any table from tree list
A new tab will open for that underlying table.
Click on Details tab.
3. Switch back to the SQL Worksheet
Now open popup describe once again

Notice the disappearance of Refresh button, row number and also the vertical scroll bar on the right side.
Regards,
Buntoro