[Addon 1.115]Transformers BETA-1 v2.0 - Convert IC2 & BC3 energy back & forth! daywalker78 Dec 5th 2012 I had a similar error, removing the ic2 folder from forestry fixed it for me.
[IC2 Exp][1.7.10] Advanced Machines 1.1.6 daywalker78 Dec 1st 2012 Transformer upgrades don't seem to work on your machines, the machines still blow up when connected to higher than LV.