If your CUSTOMTOOLS license activation fails with an Error code 2 shown in the CUSTOMTOOLS Activation Error message box, the error is caused by an insufficient user rights to the CUSTOMTOOLS license file.
Grant the Read and Write permissions for the Windows user getting the Error code 2 on the CUSTOMTOOLS activation, to the CUSTOMTOOLS license file location. The CUSTOMTOOLS License file is located in the following path:
C:\ProgramData\ATR Soft\CustomTools\Licenses