[FIXED] error when switching tabs - very specific circumstances

[Bee-liever]

this has been happening, every now and then, for quite a while but I until now I couldn't reliably reproduce the events to trigger it.

The error from the log:

Code

22/03/2017 6:10:51 PM - 10.0.14393.0 - 3.1.6289.35097 - System.NullReferenceException: Object reference not set to an instance of an object.
   at MusicBee.MusicBeeMain.#=qdiOphZpGbYTYf0L2hY62yw==(#=qMEDKbEhPkyL8Ris$PjI1i9jjde8tC1gIogQL$q8Oucg= #=qyWCgXJUSHzifEM_xIL6HCg==, #=qgFSZvo4fYaapLpQyl2GhAw== #=qIzLzZuzS01OdDCJegiHXmw==, #=qeSXYsLEQ0sn6QkGDXk01TA== #=qy0Da$NpJBPtXkp13twmzeqFvWEQ04G3aGJwuOd8P6LU=, #=qMN7kP3FXTrQReMIzDECO3FI0YT9aWWkcQvgv_BStFkA= #=qcyUqUtWFxIJB23bskAI2qA==, Boolean #=qVhBotXu6QcATvHqBhtCOWXO3U22oP_cGxvGk19nMN0o=, Boolean #=q8MAG0QspQGzGWbijUn1cgPea5jID78Mp_RrXUMKQHKg=)
   at MusicBee.MusicBeeMain.#=quIdOcYZylkSXDurPzXMc8w==(#=qAN6XKZCC4FjWJZAIbElfoKu9KLKTMoOCIMeozu5R1B8= #=qlwf0ksqUq66RbJcDmkHuiung0pK7mcBESn1nsyKOewc=, Boolean #=q1HY4I2uOUm$MhP7RMZ5$2$ok8eyVI2qNYfL$CRckohU=, #=qgFSZvo4fYaapLpQyl2GhAw== #=qcSqgu7Z0ZCBcBkZJqVYi$A==, #=qg6n4gKLcOnhUwdWQBhjlkOmpPNb39ruKNqh__2cgcGI= #=qYpejRpggs1ApViClHB39$$LdXys0my3J7Zl1mZTHmgk=, Boolean #=qu40uCixuqxWBdYaDOyTE_q4VWSWqPb7BfUtnBhAhURw=, #=qpL150Rb_YeaiqzhH2RwQ6l6LDUeAfYMbFnLWwLNV$_s= #=qISuiT6nGPQLsK4ZPadJwKg==, #=qlW8hxxe8K86qdjPIR1xmhwGY4TzdfNz5_QkdaFglAeg=[] #=q0ME_yTT5M1s1O160onrU5UOeLhafm3JrsyAOt$w8JZw=, Boolean #=q8VkhAlgq4ebX9iBYT3DAJEGa9PMog_pPdye_hH1LYq8=)

22/03/2017 6:12:37 PM - 10.0.14393.0 - 3.1.6289.35097 - System.NullReferenceException: Object reference not set to an instance of an object.
   at MusicBee.MusicBeeMain.#=qdiOphZpGbYTYf0L2hY62yw==(#=qMEDKbEhPkyL8Ris$PjI1i9jjde8tC1gIogQL$q8Oucg= #=qyWCgXJUSHzifEM_xIL6HCg==, #=qgFSZvo4fYaapLpQyl2GhAw== #=qIzLzZuzS01OdDCJegiHXmw==, #=qeSXYsLEQ0sn6QkGDXk01TA== #=qy0Da$NpJBPtXkp13twmzeqFvWEQ04G3aGJwuOd8P6LU=, #=qMN7kP3FXTrQReMIzDECO3FI0YT9aWWkcQvgv_BStFkA= #=qcyUqUtWFxIJB23bskAI2qA==, Boolean #=qVhBotXu6QcATvHqBhtCOWXO3U22oP_cGxvGk19nMN0o=, Boolean #=q8MAG0QspQGzGWbijUn1cgPea5jID78Mp_RrXUMKQHKg=)
   at MusicBee.MusicBeeMain.#=quIdOcYZylkSXDurPzXMc8w==(#=qAN6XKZCC4FjWJZAIbElfoKu9KLKTMoOCIMeozu5R1B8= #=qlwf0ksqUq66RbJcDmkHuiung0pK7mcBESn1nsyKOewc=, Boolean #=q1HY4I2uOUm$MhP7RMZ5$2$ok8eyVI2qNYfL$CRckohU=, #=qgFSZvo4fYaapLpQyl2GhAw== #=qcSqgu7Z0ZCBcBkZJqVYi$A==, #=qg6n4gKLcOnhUwdWQBhjlkOmpPNb39ruKNqh__2cgcGI= #=qYpejRpggs1ApViClHB39$$LdXys0my3J7Zl1mZTHmgk=, Boolean #=qu40uCixuqxWBdYaDOyTE_q4VWSWqPb7BfUtnBhAhURw=, #=qpL150Rb_YeaiqzhH2RwQ6l6LDUeAfYMbFnLWwLNV$_s= #=qISuiT6nGPQLsK4ZPadJwKg==, #=qlW8hxxe8K86qdjPIR1xmhwGY4TzdfNz5_QkdaFglAeg=[] #=q0ME_yTT5M1s1O160onrU5UOeLhafm3JrsyAOt$w8JZw=, Boolean #=q8VkhAlgq4ebX9iBYT3DAJEGa9PMog_pPdye_hH1LYq8=)

to reproduce:
have MB playing anything
tab A: Main panel in album and tracks view, opened to a specific album artist via library explorer
tab B: opened to a folder (via computer node in navigation panel) containing tracks by the same album artist in tab A that don't already exist in the library.
edit these tracks and send to 'Music Library' with right click menu.
try to go back to tab A and error message will pop up.

[Steven]

thanks for managing to get the details so precise for a very obscure problem as otherwise i would never have solved it.
Its fixed for the next v3.1 update

[Steven]

http://musicbee.niblseed.com/V3_1/MusicBee31_Patched.zip

[Bee-liever]

thanks for managing to get the details so precise for a very obscure problem as otherwise i would never have solved it.

yeah, it took me a while to track down what was triggering the error message so I thought it wasn't worth reporting until I could consistently reproduce those steps.
but all fixed now, thank you