Check the license in License Manager on Windows platform at first (Programs -> Innovatrics -> * -> License Manager -> Check license).
SDK cannot access the license file - Please try to load license file content into in-memory buffer and use IEngine_InitWithLicense(buffer, buffer_length) for IDKit initialization (IDKit.GetInstance(byte) in .NET or IDKit or IDKit.initWithLicense(byte) in Java).
The real HW ID from IDKit application is different than HW ID shown in LicenseManager - Please see topic Why do I get different HW ID from LicenseManager and IEngine_GetHardwareId API call?.
You can debug the problem when you set IDKit log level to 3 (IEngine_SetParameter(CFG_LOG_LEVEL, 3)). Run your sample application from console (cmd.exe) and you'll see debugging information about license validation. You can send those messages to our support in order to help diagnose the problem.
Possible sources of problem:
SDK cannot access the license file - Please try to load license file content into in-memory buffer and use IEngine_SetLicenseContent(buffer, buffer_length) before IEngine_Init() call.
If these recommendation will not solve your issue please submit support request with attached license file.