While I have had good experiences over all with the Autodesk 2015 products, as with any software there were fixes along the way. Here are my discoveries of some of those obscure and maybe not so obscure.
1) AutoCAD 2015 Cursor trails: Moving your cursor along would leave pixels everywhere. Turning off Hardware Acceleration would clear up the problem. Install the Service Pack and you can turn Hardware Acceleration back on.
2) Plant 3D 2015 Extension 1: The Plant developers are not waiting on new releases to give more functions in P3D. However, the Extension 1 was not compatible with AutoCAD Service Pack 2. You cannot even install the SP2 for a particular vertical, such as AutoCAD MEP, without it affecting P3D. But, there is a fix that fixes the fix that broke the Extension 1. After installing any AutoCAD 2015 SP2, run the .BAT file.
3) AutoCAD Electrical 2015: The error could come with several messages. The main one I have seen is: Unhandled Exception C06D007E(Delayload “acewstr.dll” Module Not Found) at address FCFA940Dh. ...