All client´s near the chunk with the BlockCuttingMachine crash immediatly after login on the server. The crash was caused by a player placing a BlockCuttingMachine from Industrialcraft 2 on QuarzGlass from Applied Energistics 2. Reading through the crash report I found that it is caused by a failing BlockProperty request where one block tries to get the material of the other. Looking through the AE2 code on the lines mentioned in the crash report, it seems to be caused by QuarzGlass requesting an invalid MaterialProperty from the IC2 machine.
As I do not have access to the IC2 code and only a medium knowledge of Java it could be on IC2´s side to fix this issue. If so please tell me and I will post the issue on their bug tracker.
Fixes #2689: Do not pass our own blockstate to the adjacent block.