If you are in a Yahoo Fantasy Hockey league then you may be experiencing technical difficulties in viewing your team's roster page. As a result you are unable to set your lines. I found this temporary solution on the Yahoo Fantasy Hockey message boards and it worked for me.
If you go to your browser View option at top. Click "Page Style" , select "No Page Style", you can adjust your roster. It's ugly but it works. Not sure what the problem is though.
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