Renaming playlist errors

[theG]

Hi Steven.
I have a playlist called "Samsung Galaxy Note 7" under folder "Samsung Galaxy Note 7" in left panel, that I use to sync with my Note 7. I'm switching device and renamed the folder without any problem to "Samsung Galaxy S8+", but when I rename the playlist in that folder to "Samsung Galaxy S8+" I get these errors:

MusicBee v3.1.6310.39337 (Win10.0), 18 avr. 2017 12:59:

#=qWKT6em25jUtEnFt5496whg==+#=qoxvxVE3nBbrqwC5zr1Fkqg==+#=q5YGSimpvVh1rm$OVirrYqJHQMbUWQmmUv11SeYLWDI4=: Le processus ne peut pas accéder au fichier car ce fichier est utilisé par un autre processus. [Z:\MusicBee\Collections\FLAC\Playlists\Samsung Galaxy S8+\Samsung Galaxy Note 7.mbp]
   à #=qWKT6em25jUtEnFt5496whg==.#=qoxvxVE3nBbrqwC5zr1Fkqg==.#=qG66EYYptfLa2r2xNJbIeEQ==.#=qKQcSvQebkxghrgARLEZ8tg==(#=qZNBu2DSfnz$35CzEuSSs3A== #=qTpRRlfN68h3QG3F$GE6Hvw==, #=qZNBu2DSfnz$35CzEuSSs3A== #=q3la1AuyCg0p45VHCZo4Ieg==, Boolean #=qid7PQSkBqvAcpk9ZUiFefw==)
   à #=qBrn0Cv_exy$FD3MOFRIowSW2aF3julebPfCqCiyNe24=.#=qlpZDHRn_FGKy6WJBILr_kA==(#=qPLgZS9XJuK2NBjBzHESwaci6dhExu0ZYdn1NxzvX_vc= #=qelRmIwmESiPaiJuZs3Ic$A==, #=qZNBu2DSfnz$35CzEuSSs3A== #=qimybsWgOsri4yaRKKhEzCA==)
   à MusicBee.Media.StorageManager.#=qoWzLnMtiP6U3s1AdSuUphQ==(#=qPLgZS9XJuK2NBjBzHESwaci6dhExu0ZYdn1NxzvX_vc= #=q_qYnulXDjVCp7r7KHEj6Ng==, #=qZNBu2DSfnz$35CzEuSSs3A== #=q20KxRLQYzWk8P_FaO_IwSw==)
   à MusicBee.Media.Library.#=qz8Oa0cmGS3bpW3XKBBxeFQ==.#=qQZAAgHvsaiPetmCTDFMVwQ==(#=qPLgZS9XJuK2NBjBzHESwaci6dhExu0ZYdn1NxzvX_vc= #=qLt7bkS4qHnUgUQghYUeRkA==, #=qZNBu2DSfnz$35CzEuSSs3A== #=q4qcwMnFkNhfksbEKIrxh2w==)
   à #=qPLgZS9XJuK2NBjBzHESwaci6dhExu0ZYdn1NxzvX_vc=.#=qYD07IJVCoNveSbW5tu8jwA==(String #=qyyLSL4wFxM$w9Jsvum5LMQ==)
   à MusicBee.Media.Library.#=qz8Oa0cmGS3bpW3XKBBxeFQ==.#=qLTnKbqvFyLR4Vph4f$QOpQ==(#=qPLgZS9XJuK2NBjBzHESwaci6dhExu0ZYdn1NxzvX_vc= #=qc_0NahanmbWt5oH3ruJy9g==, String #=qHHebJmG9P_C3ceJKlVKa0w==)
   à MusicBee.MusicBeeMain.#=qRcJmEMS8mw8moV_q8hS55g==.#=qhdVGhw2igEmEa1I$OAA9hfbuuxJDemo2aatiUvwGO3s=(#=q_fUcRSPhwi48_Cigzcoyxw== #=qT4JNlyqMTivUH2B17aq_Pg==)
   à MusicBee.MusicBeeMain.#=qRcJmEMS8mw8moV_q8hS55g==.#=qwvMEAGllK603QNJhX3i04w==(#=qxcbHByVGv7A$7L_SwUuUbSR$RfOgE8CkoKYp9Q0RJdwZOJlq98ZkmIFNP0gQ6mKF #=qshP7eX_BGa6PI497OWkH7w==)
   à #=qq4LPB0j5JKEr0FW3pOP8W7DYpvZyjs1aus$No7VZHtc=.#=qbCZWzBrrB481LgncKPVLsQ==(Boolean #=qFSu177Al$kKRWKI7C9Bfvw==)
   à #=qq4LPB0j5JKEr0FW3pOP8W7DYpvZyjs1aus$No7VZHtc=.#=qjUKyBbNjVirqHUz3OLG736wRThe$YRf$L4h36BLCpv0=(Object #=qxM1ridrXzCjSw$QPfpUi5w==, KeyEventArgs #=qhKH_5_$KckG5oJ69T6yWrg==)
   à System.Windows.Forms.Control.OnKeyDown(KeyEventArgs e)
   à #=qsB1SnDXc$BUHrXxrx6AcDhWYF6NJtuvamsuJdJDGxts=.OnKeyDown(KeyEventArgs #=q58ZBQFSCUx28RIP7zHUFow==)
   à #=qcQ2On9G19J3nnJdLy0Rhcac685RpMQtWGBczPRyrFJs=.ProcessDialogKey(Keys #=qCMcMnY3fnWXVVhKvbsVNuw==)
   à #=q$GkCRTq_VzlugJq8lyXrXLZ8Xdfg5_IT4_EM6xHHs9M=.ProcessDialogKey(Keys #=qRZiV68ZHUTR1$mBigRgU8Q==)
   à System.Windows.Forms.TextBoxBase.ProcessDialogKey(Keys keyData)
   à #=qgQKgktxiHsLMcZSOSzUBHK1syEZpE4rKfPl$ed5OeFI=.ProcessDialogKey(Keys #=qngRT$HYzIQJxpooR1iGO8w==)
   à System.Windows.Forms.Control.PreProcessMessage(Message& msg)
   à System.Windows.Forms.Control.PreProcessControlMessageInternal(Control target, Message& msg)
   à System.Windows.Forms.Application.ThreadContext.PreTranslateMessage(MSG& msg)

I press OK and get another error popup right away:

MusicBee v3.1.6310.39337 (Win10.0), 18 avr. 2017 12:59:

System.NullReferenceException: La référence d'objet n'est pas définie à une instance d'un objet.
   à #=qq4LPB0j5JKEr0FW3pOP8W7DYpvZyjs1aus$No7VZHtc=.#=qbCZWzBrrB481LgncKPVLsQ==(Boolean #=qFSu177Al$kKRWKI7C9Bfvw==)
   à #=qq4LPB0j5JKEr0FW3pOP8W7DYpvZyjs1aus$No7VZHtc=.#=qjUKyBbNjVirqHUz3OLG736wRThe$YRf$L4h36BLCpv0=(Object #=qxM1ridrXzCjSw$QPfpUi5w==, KeyEventArgs #=qhKH_5_$KckG5oJ69T6yWrg==)
   à System.Windows.Forms.Control.OnKeyDown(KeyEventArgs e)
   à #=qsB1SnDXc$BUHrXxrx6AcDhWYF6NJtuvamsuJdJDGxts=.OnKeyDown(KeyEventArgs #=q58ZBQFSCUx28RIP7zHUFow==)
   à #=q$GkCRTq_VzlugJq8lyXrXLZ8Xdfg5_IT4_EM6xHHs9M=.#=q9t9rIq9cH1c6sCi8ClJgRF2mEnbDJ079_czwg4SdyW0=(Object #=qrkNjn6bamJvvS40c_zJVpg==, KeyEventArgs #=qNUkNhy7HGygd4yoKn8H8IA==)
   à System.Windows.Forms.Control.OnKeyDown(KeyEventArgs e)
   à System.Windows.Forms.Control.ProcessKeyEventArgs(Message& m)
   à System.Windows.Forms.Control.ProcessKeyMessage(Message& m)
   à System.Windows.Forms.Control.WmKeyChar(Message& m)
   à System.Windows.Forms.Control.WndProc(Message& m)
   à System.Windows.Forms.TextBoxBase.WndProc(Message& m)
   à System.Windows.Forms.TextBox.WndProc(Message& m)
   à System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   à System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   à System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

The playlist renames fine after that, but when I reopen MusicBee, it's back to its original name.

[Steven]

i am not sure what would be locking the playlist but in any case i suggest you update to the latest patch version which i had already enhanced to retry moving a file a couple of times for another issue, and that might help in this case