window media player cannot syncronize the file the player might not support the file

i updated window media player and now i cant put songs on my mp3 player that i could before and windows says this window media player cannot syncronize the file the player might not support the file type and it did before i upgraded please help me

The newer Windows Media Players have different licensing policies and I encountered loads of problems with files that were already on my computer when I upgraded to WMP9/10. Restore your computer to before you installed Media Player 9/10 and this will allow you to transfer again. There are plenty of better players than WMP; ITunes 7 with it's "cover-flow" feature is awesome and it can be configured to up/download to any MP3 player as well. It uses the Quicktime player instead of WMP though.