If a [ or ], which are used for syntax in .ini files, are included in a folder name, problems occur when that filepath is used for anything that is recorded in .ini files. The example given in the repro steps causes the entry for the filepath to the newly set map to become incomplete due to these two characters.
I believe a more reasonable fix would be to stop users from including these characters in their folder names but it would also be helpful if the editor could catch this and handle it in some way.
This also occurred in 4.13 and 4.14 and likely every version prior
Head over to the existing AnswerHub thread and let us know what's up.