Boston area metal veterans Godsmack have been forced to cancel a string of scheduled tour dates in Europe, the band announced over the weekend, after frontman Sully Erna came down with an illness and was advised by doctors to take a week off.  The affected dates include a June 23rd appearance at the Rock A Field festival in Luxembourg and a show in Paris later that night as well as a June 26th stop in Zurich, Switzerland. Refunds, according to the band's announcement, can be obtained where tickets were purchased.