Answer: There are a few possible answers to this, here are the three most frequent ones in order of appearance:
1) You applied the Activation Code to the wrong product. Example of this? Picking A+ 220-801 instead of 220-802 or selecting one of these but wanting to activate the A+ Certfication bundle. CertBlaster has three products for A+: A+ 220-801, A+ 220-802 and the A+ Certification bundle. Each of these are recognized by three different activation keys. If you bought the bundle but try to activate one of the individual A+ products the system will see a mismatch in key and throw the error message “invalid key”.
2) You applied an activation code from LabConnection, ExamConnection, IT_LabWorks or, gasp, a competitor’s product!