Does it work? ==>
http://vnboards.ign.com/ac_utilities/b5432/112244851/p1/?2 http://vnboards.ign.com/ac_utilities/b5432/112244851/p1/?2
Nezrik is correct. The base operation of the AC Dual Client (ACDC) requires TWO installation copies of Asheron's Call. The wizard after first installing ACDC assist you in creating this second "copy" on your computer.
The error message indicates that this second copy did not get created.
Further, ACDC is attempting to use both "sessions" from the same single copy of AC you have installed on your computer .. thus the error message.
Decal is not required for using ACDC. But the information from it's export feature can be some help, in helping the rest of us to understand your computer from it's information.