Steps to replicate:
1) Go to the Output panel in the Render properties and click the Open File Browser icon at the end of the path field

2) Choose or create a new directory for storing the rendered sequence

3) Leave file name blank

Expected results:
File path should read with a trailing slash (/). When rendering (e.g. an image sequence), the individual files should be numbered and placed within the selected or created directory.

Actual results:
Rendered files are given the selected or created directory as a prefix for each file name. That is, if you created a directory named renders and intended each file in that directory to be named 0001.png, 0002.png, etc., you *actually* get a blank renders directory and each file is named renders0001.png, renders0002.png, etc.