PC vst versions of Metric Halo plugins will not open in or system hangs when loading into X3e.

I contacted MH about this and posted my reply here: http://forum.cakewalk.com...-m3093882.aspx#3149448
 
They are waiting on Cakewalk to look into it.
 
I also tested channel strip 3 in Platinum and Sonar still hangs.

At this stage I would contact cakewalk support and get an update. Please keep us updated.

Moving to Sonar forums for now, maybe others might want to comment. From the look of the quote they are effectively stating Sonar is not supported right now.

I contacted MH support about the Channel Strip plugin. MH's reply seemed quite specific about the plugin not working in X3e and waiting on a Cakewalk to "look into it":
 
"At the moment we are aware of an incompatibility with Sonar X3e. We are in touch with Cakewalk, who has informed us they will look into it when they have a chance. We are hopeful we can add compatibility in a future update of the Production Bundle. Please stay in touch."
 
It was obviously working in Sonar at one point. The OP of the thread I linked to even does a quick review.