Hello Developers.
I'm already using the Clang-D Client for some Months under Windows 11 without big issues like a crash of Code::Blocks.
Now I have installed on same Windows 11 laptop under WSL2 Ubuntu and there Xavious distribution of this nightly as already discussed above. 
After Installing the  "codeblocks-contrib" package also I  deactivated the Code-Completion and activated the Clang-D Client. 
But after closing Code::Blocks and opening it again it hang and I had to exit Ubuntu and restart it again. 
Fortunately I was able to reactivate my file ~/.config/codeblocks/default.conf by 
replacing the xml-node <CLANGD_CLIENT bool="1" /> by <CLANGD_CLIENT bool="0" />.
Now I started some experiments together with the Windows Copilot were this is the conclusion given by the Copilot:
I've been testing the Clangd_Client plugin under Linux using Code::Blocks version 25.03+svn13739~ubuntu25.04.1 from the x-psoud PPA. While the plugin works fine under Windows, enabling it on Linux consistently causes Code::Blocks to freeze during startup.
Here s a summary of what I ve tried:
- Installed codeblocks-contrib to enable Clangd_Client and other plugins.
 - Verified that clangd is installed and executable via /usr/bin/clangd.
 - Disabled potentially conflicting plugins: CodeCompletion, FileManager, MouseSap, Symbols Browser, SmartIndent, OpenFilesList.
 - Ensured a valid project with compile_commands.json is open before enabling Clangd_Client.
 - Manually inserted a complete <clangd_client> configuration block into default.conf, including the correct LLVM path and parser settings.
 - Tried launching Code::Blocks with Clangd_Client enabled and a project loaded.
 - Despite all this, Code::Blocks hangs during startup. The last console output before freezing is:
 - KeyBinder: adding missing menuItem[2565|&Help::Plugins::Clangd_Client...|]
 
This suggests the freeze occurs during menu setup, not during LSP communication. It appears to be a GUI-level issue, possibly related to wxWidgets or GTK3 event loop timing.
But when I read the line "Verified that clangd is installed and executable via /usr/bin/clangd" I became a little bit unsure and checked this again. 
My finding was that this path was not the real location of clangd but only the location of a symbolic link to /usr/lib/llvm-15/bin/clangd.
So I tried out to modify the path in my manually added <clangd_client> configuration block and exchanged the lines
		<LLVM_MASTERPATH>
			<str>
				<![CDATA[/usr/bin/clangd]]>
			</str>
		</LLVM_MASTERPATH>
  by the lines   
	<LLVM_MASTERPATH>
			<str>
				<![CDATA[/usr/lib/llvm-15/bin/clangd]]>
			</str>
		</LLVM_MASTERPATH>
And suddenly Code::Blocks started normally as wanted and Clang-D is working as desired. 
So the final workaround was to copy the clangs_client tree from my Windows 11 conf-file into the Linux conf-file and to set the LLVM_MASTERPATH to the real location of the binary and not to the location of a symbolic link .
	<clangd_client>
		<PARSER_DEFAULTS_CHANGED bool="1" />
		<PARSER_FOLLOW_LOCAL_INCLUDES bool="1" />
		<PARSER_FOLLOW_GLOBAL_INCLUDES bool="1" />
		<WANT_PREPROCESSOR bool="1" />
		<PARSE_COMPLEX_MACROS bool="1" />
		<PLATFORM_CHECK bool="1" />
		<SEMANTIC_KEYWORDS bool="0" />
		<USE_SMARTSENSE bool="1" />
		<WHILE_TYPING bool="1" />
		<AUTO_ADD_PARENTHESES bool="1" />
		<DETECT_IMPLEMENTATION bool="0" />
		<ADD_DOXGEN_COMMENT bool="0" />
		<ENABLE_HEADERS bool="1" />
		<MAX_MATCHES int="1000" />
		<FILLUP_CHARS>
			<str>
				<![CDATA[]]>
			</str>
		</FILLUP_CHARS>
		<CC_DELAY int="300" />
		<LEXER_KEYWORDS_SET1 bool="1" />
		<LEXER_KEYWORDS_SET2 bool="1" />
		<LEXER_KEYWORDS_SET3 bool="0" />
		<LEXER_KEYWORDS_SET4 bool="0" />
		<LEXER_KEYWORDS_SET5 bool="0" />
		<LEXER_KEYWORDS_SET6 bool="0" />
		<LEXER_KEYWORDS_SET7 bool="0" />
		<LEXER_KEYWORDS_SET8 bool="0" />
		<LEXER_KEYWORDS_SET9 bool="0" />
		<LOGCLANGDCLIENT_CHECK bool="0" />
		<LOGCLANGDSERVER_CHECK bool="0" />
		<LSPMSGSFOCUSONSAVE_CHECK bool="1" />
		<LSPMSGSCLEARONSAVE_CHECK bool="1" />
		<LLVM_MASTERPATH>
			<str>
				<![CDATA[/usr/lib/llvm-15/bin/clangd]]>
			</str>
		</LLVM_MASTERPATH>
		<MAX_THREADS int="1" />
		<MAX_PARSERS_WHILE_COMPILING int="0" />
		<HEADER_EXT>
			<str>
				<![CDATA[h,hpp,hxx,hh,h++,tcc,xpm]]>
			</str>
		</HEADER_EXT>
		<EMPTY_EXT bool="1" />
		<SOURCE_EXT>
			<str>
				<![CDATA[c,cpp,cxx,cc,c++]]>
			</str>
		</SOURCE_EXT>
		<USE_SYMBOLS_BROWSER bool="1" />
		<BROWSER_SHOW_INHERITANCE bool="0" />
		<BROWSER_EXPAND_NS bool="1" />
		<AS_FLOATING_WINDOW bool="0" />
		<BROWSER_TREE_MEMBERS bool="1" />
		<SCOPE_FILTER bool="1" />
		<TOOLBAR_SCOPE_LENGTH int="280" />
		<TOOLBAR_FUNCTION_LENGTH int="660" />
		<USE_DOCUMENTATION_HELPER bool="1" />
		<DOCUMENTATION_HELPER_BACKGROUND_COLOR>
			<colour r="255" g="255" b="255" />
		</DOCUMENTATION_HELPER_BACKGROUND_COLOR>
		<DOCUMENTATION_HELPER_TEXT_COLOR>
			<colour r="0" g="0" b="0" />
		</DOCUMENTATION_HELPER_TEXT_COLOR>
		<DOCUMENTATION_HELPER_LINK_COLOR>
			<colour r="0" g="0" b="255" />
		</DOCUMENTATION_HELPER_LINK_COLOR>
		<BROWSER_DISPLAY_FILTER int="1" />
		<BROWSER_SORT_TYPE int="1" />
		<SPLITTER_POS int="219" />
		<LOGPLUGININFO_CHECK bool="0" />
		<LOGPLUGINDEBUG_CHECK bool="0" />
		<USECOMPLETIONICONS_CHECK bool="1" />
		<IGNORED_DIAGNOSTICS>
			<astr>
				<s>
					<![CDATA[warning:Included header tree_node.hpp is not used directly (fix available) remove #include directive]]>
				</s>
			</astr>
		</IGNORED_DIAGNOSTICS>
	</clangd_client>
I hope this post is helpful for other users with asimilar problem and for you while thinking about a final solution. 
Best regards,
                    Eckard.