This morning I configured twitter signin module correctly.
If an anonimous user tried to signin with his twitter account, all was work correctly, but his username was "_1".
I have another site where usernames of users who signin with their twitter account are their twitter account name.
It seems the configuration is the same in both sites, but I try to reconfigure my first site. Now, when a user (or an anonimous user) try to signin with his twitter account, site says "Invalid Twitter OAuth request".
In configuration all seems to be ok,
I have tried to reinstall both twitter and twitter signin modules but error persists...what could be done??