There are several possible reasons you may experience an "Invalid" status after activating an add-on that was licensed by Third Party Licensing & Activation Toolkit.
The activation process requires writing to the registry and other hidden system locations on the computer. Because of Windows security settings and User Account Control on Windows Vista or later, these protected system locations can not be accessed by a user without administrative privileges. Typically, third-party add-ons register the add-on by requesting administrative privileges during installation but sometimes this does not happen. The solution is to right-click the LabVIEW icon and select Run as an administrator to enable administrator privileges during activation. This only needs to be done once and then LabVIEW can be run as normal during subsequent uses. Alternately, you can uninstall the add-on and re-install with both VI Package Manager and LabVIEW run as an administrator.
The licensing DLLs use a newer security certificate that is unrecognized by older, non-updated installations of Windows XP. Because of this unrecognized certificate, Windows does not think the DLL is valid and LabVIEW fails when trying to call the DLL, causing the DLL to appear invalid. The solution is to ensure that all root certificates are up to date through Windows Update.
When RegisterAddon.exe registers an add-on with LabVIEW, it checks the registry for the LabVIEW install path. In LabVIEW 2012 and earlier, if there is a registry key for a version of LabVIEW that isn't actually installed (for example a 2010 key exists but 2010 isn't installed and there are no values under the 2010 key) then RegisterAddon.exe fails. This is very commonly seen on systems that have LabVIEW FPGA and/or the Xilinx Compile tools installed. This is a bug that was fixed in LabVIEW 2013 and later. To resolve this, manually delete the empty registry keys from the system and re-register the add-on with RegisterAddon.exe.
In order for the license to be valid, the license file has to exist in the expected location. This should be installed by the installer or VI Package manager to the location [Public App Data]\National Instruments\Partners\<company name>\Licenses\<license file name>.lf. The Public App Data directory is typically a hidden folder located at C:\ProgramData.
In VI Package Manager 2012 and earlier, VIPM calls RegisterAddon.exe incorrectly, which can cause add-ons installed to LabVIEW 2012 and later not to register correctly. This was resolved in VI Package Manager 2013 and later. The solution is to upgrade to the latest version of VI Package Manager or manually call RegisterAddon.exe in the correct way.
If the above solutions don't work, you can get additional debugging information from the activation process that may help troubleshoot the issue.
Debugging RegisterAddon.exe Additional debugging information can be logged from RegisterAddon.exe by using the -d flag. The proper way to call this from the command line is RegisterAddon.exe -- -s -d -l "vi.lib\<relative path to the lvlib>". This will write debugging information to <LabVIEW>\resource\Partners\default.log which can potentially contain useful error information.
Debugging activation Additional debugging information can be logged from the activation process by adding a debug token to your LabVIEW.ini file. Open <LabVIEW>\LabVIEW.ini and add the token DPrintfLogging=True. Restart LabVIEW and attempt activation of the toolkit. Before restarting again, you may view or copy the debug log at [User Temporary]/labview_cur.txt. The [User Temporary] directory is typically located in C:\Users\<user name>\AppData\Local\Temp\. Search for the keyword "LV2P" to reveal specific items logged from the licensing process. Important: Having this token enabled may slow down your LabVIEW. Only enable this token if you are experiencing problems, and make sure to disable it once the problems are resolved.
To continue troubleshooting, you may send these two log files to the support contact for the product you are trying to activate. Support contact information can be found in the product documentation or on the LabVIEW Tools Network model page for the product. If you are the developer of a third party product and need additional help troubleshooting this problem, you can post your log files to the Third Party Licensing & Activation Toolkit community (ni.com/licensingtoolkit) or you may email the log files to the LabVIEW Tools Network team.