First off, I can see nothing syntactically wrong with your file.
But there are some traits that I (and the base game v0.2) don't recognise; "Famously" and "Idol".
Are these from Brothel King v0.3 or do you use mods for these?
In my v0.2 game they throw an error as well.
Anyway, I think also the file extension might cause an issue. Haven't tested this, but normally configuration files of girlpacks are .ini files. Yours is a .txt file. Might be that that is just due to uploading it here, but make sure its a .ini file in your girlpack. I don't know if the game checks for extensions, but better be safe than sorry.
I think one or both of these should fix your problem, since I took your data and made it an .ini and removed Famously and Idol and she shows up in-game (for sale as a slave in this case) as intended, with expected traits and all:
View attachment 3500554
By the way; to change file extensions in Windows go to your girlpack folder (or any folder) and in the top go to "View". On the right of the ribbon "Options". Second tab in the new window that opens is "View". Then make sure there is NO check mark at "Hide extensions for known file types". Click okay and your _BK file should show up as "_BK.txt". Now just change the txt part for ini and accept when Windows tells you you'r changing the filetype.