Your description of the problem is very vague.

Are you saying that all tool icons have disappeared from the Main Tool Palette - except the Selection Tool icon?

no, the tools icons are there but the only tool working is the selection tool...

I restarted etc...

no way

…it happens only on one part (voice part)…

…I restarted etc…

I suppose that the problem is document specific, not program specific - right?

I mean, the problem does not happen in other documents - right?

… the tools icons are there, but the only tool working is the selection tool …

And you have tried all the other tools - right?

speedy entry tool selected,

bar selection in the score...

wrong behaviour, isnt'it?