can you PM me a link to your settings file:
MusicBee3DemoSettings.ini in your AppData\MusicBee folder or AppData where MB is installed for portable versions
I have the same problem, no such file present, and the problem is identical with no ini files at all. Stack is:
MusicBee v3.0.5763.39538 (Win6.1), 14 pa? 2015 13:57:
System.NullReferenceException: Object reference not set to an instance of an object.
at #=qooWa3FWQCNPSamNbOkBpxD90cJ0Y40etToRFcVj8hwo=.#=qTfDHDh_jy8lmYtYr2GzmDg==.#=q4iRfPkEwTUVtte5OXt75hQ==(Int32 #=qxDElxN0K26avjIrzWV_n2Q==)
at MusicBee.MusicBeeMain.#=qu4rSWRwc$U177bTYFnaOiw==.#=qChbG7xjjwvVoXpe0m4TZbnki9pplW0xSl$L1yWaQhfs=(Boolean #=qrsJOQo_08Rgvba8upQqWMQ==)
at MusicBee.MusicBeeMain.#=q2hSjbFceMfx80fu70eT2fkNqUWXyCmqprqK36ksAFGU=()
at MusicBee.MusicBeeMain.#=qnL0iLJw5FkPzOyUYCXalXw==(#=qTOE2YRaKi$qdLlKQnzDpQ702CaZYrqgdzRhzH78XgmU= #=qphosGeRGgor78HYPXYDbbFSN8MmKwB7O2WeKNlsJgXU=, Boolean #=qSiaYMGZ7cBHTMQkeJuCa2tUfzLmtyH76PR_ByzCQCeY=, #=qKtNw_k92py4GtOezZ_GR7A== #=q8H0BOENeqTGeTq7VAw58gA==, #=qDv8n84t1hqzYP3FJepOAH1_axVfyLMvTvgaSEB2Oek8= #=q4O6Wmf6B29_uB3CB295$WAFBbmc5oQ6CeG6X7guggqs=, #=qLOmbIl_wJA_6tXOEgUe3r404XY7GABgIMMvmWWKfVSM= #=qE1duEOa3yqLorm$yWOlsHw==, #=qRsCqdjzwKuj6fnYFbSg5opDW_b0BJAwpcCtBpRfc0YY=[] #=q0_s0lBbfEl4ZEkvbQcPdAy5nsusrZp9dQwonPBo6OIE=, Boolean #=qaRqjDPbSNhEmjciIlFgfGEHuGm8Bc08ye2QpDvvm4TM=)
at MusicBee.MusicBeeMain..ctor()
at MusicBee.MusicBeeApplication.#=qrf87gj5eYk_Rv7W$mA2mIg==(String[] #=qEHih72XljlOrYnTcGPnuIw==)