UPDATE: Minor change that adds a test for either a null value (None) or a string value of 'None'. If  Is detected to be either of these values, its value is then set to an empty string ('') so that the string concatenation performed on line 885 (in my version of the script) doesn't break the script. I've tested this change on my machine and the script continues to work perfectly. I'll leave a comment on this commit on Github that shows the values in my 'quicktile.cfg' file.