Symptoms
At compile time you receive an error message that the “license signature is invalid”
Cause
This is most often caused by users who have manually modified the license file. Our license files are cryptographicaly hashed to prevent modification, so any changes such as changing a machie ID or version number will break the license. It may also sometimes happen when using an older license file with a new version of the SDK.
Resolution
You will need to generate a new license file by using the DotImage Activation Wizard.
Please do not ever manually modify the contents of the license files or rename them.
When you use this utility it will generate a new license file for you with the proper license signature for the current version of the software you have installed. Please be sure to overwrite any of the existing license files that you during this process. Once you have done this you will need to do a “Rebuild” of your project so that it pulls in the updated license file.
Workaround
If the above does not work it is likely due to the cause that you have license files in none standard locations on your system. With the 5.0b release of the software we made an addition to the activation wizard that will search your system for Atalasoft license files and remove them. Please run this utility remove all the files that it finds and then follow the above instructions.
If you have gone through with the offline activation process, there is a chance the license file was generated with the wrong type of signature. Open your license file in notepad and look for a V2 signature flag. If the flag is not present and your license file version is greater than 4, please contact support.
Original Article:
Q10174 - HOWTO: Invalid License Signature