IMP Fatal Error on 2.3.6

[David B. Hughes]

I've gone over my install and documention serveral times,
however I keep getting this error when trying to bring up IMP.
The test.php returned back all favorable showings and program
support.

Fatal error: Undefined class name 'lang' in
/usr/local/apache/htdocs/horde/imp/lib/base.php on line 38

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  CyberActive Solutions, Inc.
      David B. Hughes
       President CSI
      (757) 599-5502
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