Ceniza, thanks for looking into this.
I had already stepped back to build 4429 which works fine on my side. I tried today's build again and it produced the same error under Windows 2000. I then temporarily renamed my current CodeBlock directory in order to create a new one, in case some forgotten file left behind was causing the problem. I extracted today's build, copied mingwm10.dll and wxmsw28u_gcc_cb.dll to it and tried again: same error, the help_plugin.dll failed to load.
Next, I borrowed my wife's laptop which runs Windows XP (SP2) Home Edition on an AMD Ahlon 64 Processor 3000+ under 512 MB of RAM. I installed today's nightly to it. The help plugin failed to load here as well. Here is the log file which shows the error in question:
Manager initialized
Scanning for lexers in C:\Documents and Settings\Lysa 2\Application Data\codeblocks/share/codeblocks/lexers/...
Found 0 lexers
Scanning for lexers in C:\Program Files\CodeBlocks/share/codeblocks/lexers/...
Found 29 lexers
Configured 0 tools
Scanning for plugins in C:\Documents and Settings\Lysa 2\Application Data\codeblocks/share/codeblocks/plugins...
Found 0 plugins
Scanning for plugins in C:\Program Files\CodeBlocks/share/codeblocks/plugins...
ERROR: C:\Program Files\CodeBlocks/share/codeblocks/plugins/help_plugin.dll: not loaded (missing symbols?)
Found 27 plugins
Loading: AStylePlugin Autosave BYOGames CB_Koders ClassWizard CodeCompletion CodeSnippets CodeStat Compiler copystrings Debugger FilesExtensionHandler DevPakUpdater cbDragScroll EnvVars Exporter cbKeyBinder lib_finder Profiler ProjectsImporter RegExTestbed ScriptedWizard SymTab ToDoList wxSmith wxSmithMime wxSmithContribItems WindowsXPLookNFeel
Running startup script
Script/function 'edit_startup_script.script' registered under menu '&Settings/-Edit startup script'
Finally, I downloaded the replacement file from your last message. An error window opened with these details in the log:
10:45:52: Can not enumerate files in directory 'C:\Documents and Settings\Administrator\Application Data\codeblocks/share/codeblocks/lexers/' (error 3: the system cannot find the path specified.)
10:45:52: Resource files must have same version number!
10:45:53: Failed to load shared library 'C:\Program Files\CodeBlocks/share/codeblocks/plugins/help_plugin.dll' (error 127: the specified procedure could not be found.)
EDIT 1: My PC does not have a 'C:\Documents and Settings\Administrator\Application Data\codeblocks/share/codeblocks/lexers/' directory.
EDIT 2: I note the odd alternate use of forward and backward slashes in the names...