I had the same thing happen to two pairs of Lowa boots, the Renegade and Klondike models. On mine, the midsole completely disintegrated, making repair nearly impossible.

If it's just the glue, however, it might be worth trying to repair. If you're going to try to do it yourself, Barge Cement is the stuff to use, and readily available at hardware stores. I've reglued a number of soles with it and never had it come apart. Tanner's Bond contact cement, available at leather supply shops, is good, too, and much like the original Barge Cement.