This error message usually occurs due to not having sufficient privileges on your operating system to access the following default license directories:
C:\Documents & Settings\All Users\ThinkBuzan
C:\Documents & Settings\All Users\JSoft
Macintosh HD/Library/Application Support/ThinkBuzan
This issue can be resolved in nearly all cases by simply ensuring you are logged in to an administrator's account when running iMindMap. If running Windows Vista, 7 or 8 you may be able to resolve the issue by right clicking on the iMindMap desktop icon and selecting 'Run As Administrator' and continue to activate your license.