How to fix "Not a valid key" -2 failure on silent installation on Linux?

I am receiving a "not a valid key" error when installing on a Centos 7 machine using

$ ./install -inputFile installer_input.txt -agreeToLicense yes -silent yes

The install log below mentions a MATLAB Answer but doesn't give the URL. Please assist.

```

(May 29, 2020 02:53:23) Reading from /home/<homedir>/archives

(May 29, 2020 02:53:23) Starting local product/component search in download directory

(May 29, 2020 02:53:23) Searching for archives...

(May 29, 2020 02:53:23) Reading /home/<homedir>/archives

(May 29, 2020 02:53:23) 3 files found in /home/<homedir>/archives

(May 29, 2020 02:53:23) Archive search complete. 3 total files found.

(May 29, 2020 02:53:23) Not a valid key. For more information on how to generate a valid key see this MATLAB Answer.

(May 29, 2020 02:53:23) Exiting with status -2

(May 29, 2020 02:53:23) End - Unsuccessful

(May 29, 2020 02:53:23) Something Unexpected Occurred: To resolve this issue, contact Customer Support.

at com.mathworks.matlab_installer.ExceptionHandlerImpl.convertException(Unknown Source)

at com.mathworks.matlab_installer.ExceptionHandlerImpl.processException(Unknown Source)

at com.mathworks.installservicehandler.context.ExceptionInterceptor.invoke(ExceptionInterceptor.java:30)

at com.google.inject.internal.InterceptorStackCallback$InterceptedMethodInvocation.proceed(InterceptorStackCallback.java:75)

at com.google.inject.internal.InterceptorStackCallback.intercept(InterceptorStackCallback.java:55)

at com.mathworks.matlab_installer.services.MATLABInstallerInitServices$$EnhancerByGuice$$9e264a69.finalizeSession()

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

at java.lang.reflect.Method.invoke(Method.java:498)

at com.mathworks.installservicehandler.JsonPassThroughResponseWrapper.getData(JsonPassThroughResponseWrapper.java:24)

at com.mathworks.installservicehandler.JsonPassThroughResponseWrapper.getData(JsonPassThroughResponseWrapper.java:10)

at com.mathworks.installservicehandler.InstallServiceHandlerClient.executeService(InstallServiceHandlerClient.java:18)

at com.mathworks.matlab_installer.MatlabInstallerClient$14.executeService(Unknown Source)

at com.mathworks.installjscommon.InstallerClientUtility.executeGetNextStateInSequence(Unknown Source)

at com.mathworks.matlab_installer.MatlabInstallerClient.clientMain(Unknown Source)

Caused by: java.lang.Exception: Generic Error: Something Unexpected Occurred

... 16 more

```

[Words Wordsworth]

Answering my own question, I thought that supplying the license.dat file to fire up the network license manager was sufficient. Turns out I also needed to speciffy the file installation key in the installer_input.txt file as well. Once I did this, installation worked.