TIBCO Spotfire Statistics Services TERR engine fails to start, with Error : error creating TERR engine (EvaluationError): Error: could not find function ".setLockedVar"

TIBCO Spotfire Statistics Services TERR engine fails to start, with Error : error creating TERR engine (EvaluationError): Error: could not find function ".setLockedVar"

A TIBCO Spotfire Statistics Services (TSSS) instance's TIBCO Enterprise Runtime for R (TERR) statistical engine fails to start, with the following error:

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error creating TERR engine (EvaluationError): Error: could not find function ".setLockedVar"Error: could not find function ".setLockedVar"
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This error can appear in the TIBCO Spotfire Statistics Services (TSSS) log file (SplusServer.log), as well as in an interactive TERR Console session launched from the TERR executable file in the TSSS installation directory tree, such as (for example):

C:\Program Files\TIBCO\statsvcs711\TERR711DEMO\engines\Terr\bin\TERR.exe)

The error indicates that an essential component in the TERR engine may have been corrupted.

Cause:

The .setLockedVar() function is in the "methods" package that is part of core TERR.  It is needed as part of the startup sequence for a TERR session.

This issue may occur if you replaced the built-in core TERR package named "methods" with an incompatible (or old) version of the "methods" package, or with some other package that also uses the "methods" name.  (This could happen if you copy an existing package folder into the TERR instance's "library" folder using Windows Explorer, a shell command, or a shell script, for example.)
  Avoid replacing TERR's built-in core packages in its "library" folder.  

To recover from this error, you can check below options:

Option 1: 

If you have made a backup of the "library" folder (for example: C:\Program Files\TIBCO\statsvcs711\TERR711DEMO\engines\Terr\library) before you changed anything under the "library" folder, then you can copy the original packages from that backup "library" folder back into the changed "library" folder, as long as you have not replaced any of the base packages in the backup library folder.

Option 2: 

If you did not make a backup copy of the "library" folder before changing anything under "library" folder, then you can perform one of the following steps:

i) Apply the latest cumulative hotfix for your current TSSS version, if it is available. This will replace its "Terr" folder (For example: C:\Program Files\TIBCO\statsvcs711\TERR711DEMO\engines\Terr) with an original version that contains the correct base packages in its "library" subfolder.

Note:  Be sure to follow the hotfix instructions when using this recovery method.

ii) If the TSSS hotfix is not available, then you will need to uninstall and reinstall the TSSS instance.