diff --git a/indra/newview/fsfloaterim.cpp b/indra/newview/fsfloaterim.cpp
index 089e18bfc6..5cc9e6bad2 100644
--- a/indra/newview/fsfloaterim.cpp
+++ b/indra/newview/fsfloaterim.cpp
@@ -482,9 +482,13 @@ void FSFloaterIM::onHistoryButtonClicked()
 {
 	lldebugs << "FSFloaterIM::onHistoryButtonClicked" << llendl;
 	if (gSavedSettings.getBOOL("FSUseBuiltInHistory"))
+	{
 		LLFloaterReg::showInstance("preview_conversation", mSessionID, true);
+	}
 	else
-		LLAvatarActions::viewChatHistoryExternally(mSessionID);
+	{
+		gViewerWindow->getWindow()->openFile(LLLogChat::makeLogFileName(LLIMModel::instance().getHistoryFileName(mSessionID)));
+	}
 }
 
 // support sysinfo button -Zi
diff --git a/indra/newview/llavataractions.cpp b/indra/newview/llavataractions.cpp
index 592d3761fe..e669822069 100644
--- a/indra/newview/llavataractions.cpp
+++ b/indra/newview/llavataractions.cpp
@@ -1125,7 +1125,18 @@ void LLAvatarActions::viewChatHistory(const LLUUID& id)
 
 		LLAvatarNameCache::get(id, &avatar_name);
 		extended_id[LL_FCP_COMPLETE_NAME] = avatar_name.getCompleteName();
-		extended_id[LL_FCP_ACCOUNT_NAME] = avatar_name.getAccountName();
+		// <FS:Ansariel> [Legacy IM logfile names]
+		//extended_id[LL_FCP_ACCOUNT_NAME] = avatar_name.getAccountName();
+		if (gSavedSettings.getBOOL("UseLegacyIMLogNames"))
+		{
+			std::string avatar_user_name = avatar_name.getUserName();
+			extended_id[LL_FCP_ACCOUNT_NAME] = avatar_user_name.substr(0, avatar_user_name.find(" Resident"));;
+		}
+		else
+		{
+			extended_id[LL_FCP_ACCOUNT_NAME] = avatar_name.getAccountName();
+		}
+		// </FS:Ansariel> [Legacy IM logfile names]
 		LLFloaterReg::showInstance("preview_conversation", extended_id, true);
 	}
 }
@@ -1136,7 +1147,22 @@ void LLAvatarActions::viewChatHistoryExternally(const LLUUID& id)
 {
 	if (LLLogChat::isTranscriptExist(id))
 	{
-		gViewerWindow->getWindow()->openFile(LLLogChat::makeLogFileName(LLIMModel::instance().getHistoryFileName(id)));
+		LLAvatarName av_name;
+
+		if (LLAvatarNameCache::get(id, &av_name))
+		{
+			std::string history_filename;
+			if (gSavedSettings.getBOOL("UseLegacyIMLogNames"))
+			{
+				std::string user_name = av_name.getUserName();
+				history_filename = user_name.substr(0, user_name.find(" Resident"));;
+			}
+			else
+			{
+				history_filename = LLCacheName::buildUsername(av_name.getUserName());
+			}
+			gViewerWindow->getWindow()->openFile(LLLogChat::makeLogFileName(history_filename));
+		}
 	}
 }
 // </FS:CR>
diff --git a/indra/newview/llconversationloglist.cpp b/indra/newview/llconversationloglist.cpp
index 542302bc40..89c1a3d7f6 100755
--- a/indra/newview/llconversationloglist.cpp
+++ b/indra/newview/llconversationloglist.cpp
@@ -35,6 +35,8 @@
 #include "llviewermenu.h"
 #include "lltrans.h"
 #include "llviewercontrol.h"	// <FS:CR>
+#include "llviewerwindow.h"
+#include "llwindow.h"
 
 static LLDefaultChildRegistry::Register<LLConversationLogList> r("conversation_log_list");
 
@@ -351,7 +353,8 @@ void LLConversationLogList::onCustomAction(const LLSD& userdata)
 	// <FS:CR> Open conversation history externally
 	else if ("chat_history_external")
 	{
-		LLAvatarActions::viewChatHistoryExternally(selected_conversation_participant_id);
+		gViewerWindow->getWindow()->openFile(LLLogChat::makeLogFileName(
+			LLConversationLog::getInstance()->getConversation(selected_conversation_session_id)->getHistoryFileName()));
 	}
 	// </FS:CR>
 }
diff --git a/indra/newview/llfloaterconversationpreview.cpp b/indra/newview/llfloaterconversationpreview.cpp
index 5282a07e80..df6b379545 100755
--- a/indra/newview/llfloaterconversationpreview.cpp
+++ b/indra/newview/llfloaterconversationpreview.cpp
@@ -40,6 +40,7 @@
 #include "llavataractions.h"
 #include "llviewerwindow.h"
 #include "llwindow.h"
+#include "llconversationlog.h"
 // </FS:CR>
 
 const std::string LL_FCP_COMPLETE_NAME("complete_name");
@@ -84,6 +85,8 @@ BOOL LLFloaterConversationPreview::postBuild()
 		name = LLTrans::getString("NearbyChatTitle");
 		file = "chat";
 	}
+	// <FS:Ansariel> Remember used log file name
+	mFileName = file;
 
 	LLStringUtil::format_map_t args;
 	args["[NAME]"] = name;
@@ -205,12 +208,5 @@ void LLFloaterConversationPreview::onMoreHistoryBtnClick()
 // <FS:CR> Open chat history externally
 void (LLFloaterConversationPreview::onBtnOpenExternal())
 {
-	if (mSessionID.notNull())
-	{
-		LLAvatarActions::viewChatHistoryExternally(mSessionID);
-	}
-	else
-	{
-		gViewerWindow->getWindow()->openFile(LLLogChat::makeLogFileName("chat"));
-	}
+	gViewerWindow->getWindow()->openFile(LLLogChat::makeLogFileName(mFileName));
 }
diff --git a/indra/newview/llfloaterconversationpreview.h b/indra/newview/llfloaterconversationpreview.h
index 13dc0d4f61..249da56369 100755
--- a/indra/newview/llfloaterconversationpreview.h
+++ b/indra/newview/llfloaterconversationpreview.h
@@ -66,6 +66,9 @@ private:
 	std::list<LLSD> mMessages;
 	std::string		mAccountName;
 	std::string		mCompleteName;
+
+	// <FS:Ansariel> Remember used log file name
+	std::string		mFileName;
 };
 
 #endif /* LLFLOATERCONVERSATIONPREVIEW_H_ */
diff --git a/indra/newview/lllogchat.cpp b/indra/newview/lllogchat.cpp
index f22e88e724..a54badb683 100755
--- a/indra/newview/lllogchat.cpp
+++ b/indra/newview/lllogchat.cpp
@@ -673,8 +673,21 @@ bool LLLogChat::isTranscriptExist(const LLUUID& avatar_id)
 	{
 		LLAvatarName avatar_name;
 		LLAvatarNameCache::get(avatar_id, &avatar_name);
-		std::string avatar_user_name = avatar_name.getAccountName();
-		std::replace(avatar_user_name.begin(), avatar_user_name.end(), '.', '_');
+		// <FS:Ansariel> [Legacy IM logfile names]
+		//std::string avatar_user_name = avatar_name.getAccountName();
+		//std::replace(avatar_user_name.begin(), avatar_user_name.end(), '.', '_');
+		std::string avatar_user_name;
+		if (gSavedSettings.getBOOL("UseLegacyIMLogNames"))
+		{
+			avatar_user_name = avatar_name.getUserName();
+			avatar_user_name = avatar_user_name.substr(0, avatar_user_name.find(" Resident"));;
+		}
+		else
+		{
+			avatar_user_name = avatar_name.getAccountName();
+			std::replace(avatar_user_name.begin(), avatar_user_name.end(), '.', '_');
+		}
+		// <//FS:Ansariel> [Legacy IM logfile names]
 
 		BOOST_FOREACH(std::string& transcript_file_name, list_of_transcriptions)
 		{