Theme conflicts with coursepress pro - chained payment multisite

Support remains active on this live site..
Mulitsite - NBT - Gridmarket...
Coursepress causes theme to break
Solution required ASAP

Will be used on a number of sites using NBT - likely Gridmarket theme

So need a fix or a way to force CPressPro to use its own theme when installed across a network..

Live site Previous support on other issues remain waiting for this Major stumbling block..