  In this paper we consider orbifold compactifications of M-theory on $S^1/{\bf
Z}_2\times T^4/{\bf Z}_2$. We discuss solutions of the local anomaly matching
conditions by twisted vector, tensor and hypermultiplets confined on the local
orbifold six-planes. In addition we consider phase-transitions among different
solutions which are mediated by M-theory fivebranes which touch the local
orbifold planes and are converted there to gauge instantons.
