[TYPO3] extension manager disappears

[Tony Lush]

I have two demo installs of TYPO3 sharing the source files, but having 
separate databases and folders for the sites.

One site is the standard FC Bigfeets site, and the other is a new blank site 
in which I am trying to install the zenlight2col template.

The Bigfeets site is working, but now when I go to admin and select the Ext 
Manager link the right hand window is empty.
The extension definition line in localconf.php reads:
$TYPO3_CONF_VARS['EXT']['extList'] = 
'tsconfig_help,context_help,extra_page_cm_options,rte,impexp,sys_note,tstempla
te,tstemplate_ceditor,tstemplate_info,tstemplate_objbrowser,tstemplate_analyze
r,tstemplate_styler,func_wizards,wizard_crpages,wizard_sortpages,lowlevel,inst
all,belog,beuser,phpmyadmin,aboutmodules,imagelist,setup,taskcenter,sys_notepa
d,taskcenter_recent,taskcenter_rootlist,info_pagetsconfig,viewpage,tt_guest,mi
ninews,tt_board,sys_todos,sys_workflows,conf_userts';

*But* I see an additional line as below:

// Updated by TYPO3 Install Tool 14-03-2006 08:11:14
$TYPO3_CONF_VARS['EXT']['extList'] = 
'tsconfig_help,context_help,extra_page_cm_options,rte,impexp,sys_note,tstempla
te,tstemplate_ceditor,tstemplate_info,tstemplate_objbrowser,tstemplate_analyze
r,tstemplate_styler,func_wizards,wizard_crpages,wizard_sortpages,lowlevel,inst
all,belog,beuser,phpmyadmin,aboutmodules,imagelist,setup,taskcenter,sys_notepa
d,taskcenter_recent,taskcenter_rootlist,info_pagetsconfig,viewpage,tt_guest,mi
ninews,tt_board,sys_todos,sys_workflows,conf_userts,bk_cssstyledcontent,rtehtm
larea';       // Modified or inserted by TYPO3 Extension Manager. 
$TYPO3_CONF_VARS['EXT']['extConf']['rtehtmlarea'] = 
'a:14:{s:21:"noSpellCheckLanguages";s:23:"ja,km,ko,lo,th,zh,b5,gb";s:15:"Aspel
lDirectory";s:15:"/usr/bin/aspell";s:17:"defaultDictionary";s:2:"en";s:14:"dic
tionaryList";s:2:"en";s:18:"HTMLAreaPluginList";s:198:"TableOperations, 
SpellChecker, ContextMenu, SelectColor, TYPO3Browsers, InsertSmiley, 
FindReplace, RemoveFormat, CharacterMap, QuickTag, InlineCSS, DynamicCSS, 
UserElements, Acronym, 
TYPO3HtmlParser";s:20:"defaultConfiguration";s:105:"Typical (Most commonly 
used features are enabled. Select this option if you are unsure which one to 
use.)";s:12:"enableImages";s:1:"0";s:22:"enableMozillaExtension";s:1:"1";s:16:
"forceCommandMode";s:1:"0";s:15:"enableDebugMode";s:1:"0";s:23:"enableCompress
edScripts";s:1:"1";s:20:"mozAllowClipboardUrl";s:114:"http://releases.mozilla.
org/pub/mozilla.org/extensions/allowclipboard_helper/allowclipboard_helper-
0.5.3-
fx+mz.xpi";s:18:"plainImageMaxWidth";s:3:"640";s:19:"plainImageMaxHeight";s:3:
"680";}';	//  Modified or inserted by TYPO3 Extension Manager.
// Updated by TYPO3 Extension Manager 15-03-2006 07:55:45

I started uploading (but not installing yet) extensions in the other demo 
site (dummy) and now the window has gone blank also. 

Its extensions config line reads:
$TYPO3_CONF_VARS['EXT']['extList'] = 
'tsconfig_help,context_help,extra_page_cm_options,rte,impexp,sys_note,tstempla
te,tstemplate_ceditor,tstemplate_info,tstemplate_objbrowser,tstemplate_analyze
r,tstemplate_styler,func_wizards,wizard_crpages,wizard_sortpages,lowlevel,inst
all,belog,beuser,phpmyadmin,aboutmodules,imagelist,setup,taskcenter,sys_notepa
d,taskcenter_recent,taskcenter_rootlist,info_pagetsconfig,viewpage';


Does anyone have any suggestions? typo3_src-3.8.1

Thank you -- Tony Lush