diff --git a/autobuild.xml b/autobuild.xml
index 7581f719dc3..c52fc65176f 100644
--- a/autobuild.xml
+++ b/autobuild.xml
@@ -1040,11 +1040,11 @@
               <key>creds</key>
               <string>github</string>
               <key>hash</key>
-              <string>243709fbbb58a91dca81d16df650e9c6ff910d0d</string>
+              <string>da318f0813e4126d90e35b22a8dce235e908707a</string>
               <key>hash_algorithm</key>
               <string>sha1</string>
               <key>url</key>
-              <string>https://api.github.com/repos/secondlife/3p-kdu/releases/assets/202118207</string>
+              <string>https://api.github.com/repos/secondlife/3p-kdu/releases/assets/208381808</string>
             </map>
             <key>name</key>
             <string>darwin64</string>
@@ -1056,11 +1056,11 @@
               <key>creds</key>
               <string>github</string>
               <key>hash</key>
-              <string>7fd0a7ee71a4e76b49e31b75f8622852324d58a4</string>
+              <string>1ba58cf884726dfdf02a7662d52f1befe3f16d44</string>
               <key>hash_algorithm</key>
               <string>sha1</string>
               <key>url</key>
-              <string>https://api.github.com/repos/secondlife/3p-kdu/releases/assets/202118208</string>
+              <string>https://api.github.com/repos/secondlife/3p-kdu/releases/assets/208381812</string>
             </map>
             <key>name</key>
             <string>linux64</string>
@@ -1072,15 +1072,31 @@
               <key>creds</key>
               <string>github</string>
               <key>hash</key>
-              <string>8c475dd9616c7e0e3029cc38aefc1e0ab34d2e73</string>
+              <string>e8d693089b9ecd15b6644f13ada7ae7c317944df</string>
               <key>hash_algorithm</key>
               <string>sha1</string>
               <key>url</key>
-              <string>https://api.github.com/repos/secondlife/3p-kdu/releases/assets/202118209</string>
+              <string>https://api.github.com/repos/secondlife/3p-kdu/releases/assets/208381814</string>
             </map>
             <key>name</key>
             <string>windows64</string>
           </map>
+          <key>linux</key>
+          <map>
+            <key>archive</key>
+            <map>
+              <key>creds</key>
+              <string>github</string>
+              <key>hash</key>
+              <string>85e294becce8b2ac5d2e5e052b0e21ff865d1108</string>
+              <key>hash_algorithm</key>
+              <string>sha1</string>
+              <key>url</key>
+              <string>https://api.github.com/repos/secondlife/3p-kdu/releases/assets/208381806</string>
+            </map>
+            <key>name</key>
+            <string>linux</string>
+          </map>
         </map>
         <key>license</key>
         <string>Kakadu</string>
@@ -1089,7 +1105,7 @@
         <key>copyright</key>
         <string>Kakadu software</string>
         <key>version</key>
-        <string>8.4.1.11540433907</string>
+        <string>8.4.1.11976899217</string>
         <key>name</key>
         <string>kdu</string>
         <key>description</key>
diff --git a/indra/llfilesystem/lldir.cpp b/indra/llfilesystem/lldir.cpp
index 06f5dd2f771..ea33a3bb906 100644
--- a/indra/llfilesystem/lldir.cpp
+++ b/indra/llfilesystem/lldir.cpp
@@ -43,7 +43,7 @@
 #include "lldiriterator.h"
 #include "stringize.h"
 #include "llstring.h"
-#include <filesystem>
+#include <boost/filesystem.hpp>
 #include <boost/range/begin.hpp>
 #include <boost/range/end.hpp>
 #include <boost/assign/list_of.hpp>
@@ -103,24 +103,24 @@ std::vector<std::string> LLDir::getFilesInDir(const std::string &dirname)
     //Returns a vector of fullpath filenames.
 
 #ifdef LL_WINDOWS // or BOOST_WINDOWS_API
-    std::filesystem::path p(ll_convert<std::wstring>(dirname));
+    boost::filesystem::path p(ll_convert<std::wstring>(dirname));
 #else
-    std::filesystem::path p(dirname);
+    boost::filesystem::path p(dirname);
 #endif
 
     std::vector<std::string> v;
 
-    std::error_code ec;
-    if (std::filesystem::exists(p, ec) && ec.value() == 0)
+    boost::system::error_code ec;
+    if (exists(p, ec) && !ec.failed())
     {
-        if (is_directory(p, ec) && ec.value() == 0)
+        if (is_directory(p, ec) && !ec.failed())
         {
-            std::filesystem::directory_iterator end_iter;
-            for (std::filesystem::directory_iterator dir_itr(p);
+            boost::filesystem::directory_iterator end_iter;
+            for (boost::filesystem::directory_iterator dir_itr(p);
                  dir_itr != end_iter;
                  ++dir_itr)
             {
-                if (std::filesystem::is_regular_file(dir_itr->status()))
+                if (boost::filesystem::is_regular_file(dir_itr->status()))
                 {
                     v.push_back(dir_itr->path().filename().string());
                 }
@@ -197,24 +197,24 @@ U32 LLDir::deleteDirAndContents(const std::string& dir_name)
     try
     {
 #ifdef LL_WINDOWS // or BOOST_WINDOWS_API
-        std::filesystem::path dir_path(ll_convert<std::wstring>(dir_name));
+        boost::filesystem::path dir_path(ll_convert<std::wstring>(dir_name));
 #else
-        std::filesystem::path dir_path(dir_name);
+        boost::filesystem::path dir_path(dir_name);
 #endif
 
-       if (std::filesystem::exists(dir_path))
+       if (boost::filesystem::exists(dir_path))
        {
-          if (!std::filesystem::is_empty(dir_path))
+          if (!boost::filesystem::is_empty(dir_path))
           {   // Directory has content
-             num_deleted = (U32)std::filesystem::remove_all(dir_path);
+             num_deleted = (U32)boost::filesystem::remove_all(dir_path);
           }
           else
           {   // Directory is empty
-              std::filesystem::remove(dir_path);
+             boost::filesystem::remove(dir_path);
           }
        }
     }
-    catch (std::filesystem::filesystem_error &er)
+    catch (boost::filesystem::filesystem_error &er)
     {
         LL_WARNS() << "Failed to delete " << dir_name << " with error " << er.code().message() << LL_ENDL;
     }
diff --git a/indra/llfilesystem/lldiriterator.cpp b/indra/llfilesystem/lldiriterator.cpp
index 28a93f1446d..e8c37389d2a 100644
--- a/indra/llfilesystem/lldiriterator.cpp
+++ b/indra/llfilesystem/lldiriterator.cpp
@@ -28,9 +28,9 @@
 
 #include "fix_macros.h"
 #include "llregex.h"
-#include <filesystem>
+#include <boost/filesystem.hpp>
 
-namespace fs = std::filesystem;
+namespace fs = boost::filesystem;
 
 static std::string glob_to_regex(const std::string& glob);
 
diff --git a/indra/llfilesystem/lldiskcache.cpp b/indra/llfilesystem/lldiskcache.cpp
index 417577369fb..e971e1885a2 100644
--- a/indra/llfilesystem/lldiskcache.cpp
+++ b/indra/llfilesystem/lldiskcache.cpp
@@ -34,7 +34,7 @@
 #include "llapp.h"
 #include "llassettype.h"
 #include "lldir.h"
-#include <filesystem>
+#include <boost/filesystem.hpp>
 #include <chrono>
 
 #include "lldiskcache.h"
@@ -83,7 +83,7 @@ LLDiskCache::LLDiskCache(const std::string& cache_dir,
 // garbage.)
 
 // Other situation: B is trimming the cache and A wants to read a file that is
-// about to get deleted. std::filesystem::remove does whatever it is doing
+// about to get deleted. boost::filesystem::remove does whatever it is doing
 // before actually deleting the file. If A opens the file before the file is
 // actually gone, the OS call from B to delete the file will fail since the OS
 // will prevent this. B continues with the next file. If the file is already
@@ -96,10 +96,10 @@ void LLDiskCache::purge()
         LL_INFOS() << "Total dir size before purge is " << dirFileSize(sCacheDir) << LL_ENDL;
     }
 
-    std::error_code ec;
+    boost::system::error_code ec;
     auto start_time = std::chrono::high_resolution_clock::now();
 
-    typedef std::pair<std::filesystem::file_time_type, std::pair<uintmax_t, std::string>> file_info_t;
+    typedef std::pair<std::time_t, std::pair<uintmax_t, std::string>> file_info_t;
     std::vector<file_info_t> file_info;
 
 #if LL_WINDOWS
@@ -107,23 +107,23 @@ void LLDiskCache::purge()
 #else
     std::string cache_path(sCacheDir);
 #endif
-    if (std::filesystem::is_directory(cache_path, ec) && ec.value() == 0)
+    if (boost::filesystem::is_directory(cache_path, ec) && !ec.failed())
     {
-        std::filesystem::directory_iterator iter(cache_path, ec);
-        while (iter != std::filesystem::directory_iterator() && ec.value() == 0)
+        boost::filesystem::directory_iterator iter(cache_path, ec);
+        while (iter != boost::filesystem::directory_iterator() && !ec.failed())
         {
-            if (std::filesystem::is_regular_file(*iter, ec) && ec.value() == 0)
+            if (boost::filesystem::is_regular_file(*iter, ec) && !ec.failed())
             {
                 if ((*iter).path().string().find(CACHE_FILENAME_PREFIX) != std::string::npos)
                 {
-                    uintmax_t file_size = std::filesystem::file_size(*iter, ec);
-                    if (ec.value() != 0)
+                    uintmax_t file_size = boost::filesystem::file_size(*iter, ec);
+                    if (ec.failed())
                     {
                         continue;
                     }
                     const std::string file_path = (*iter).path().string();
-                    const std::filesystem::file_time_type file_time = std::filesystem::last_write_time(*iter, ec);
-                    if (ec.value() != 0)
+                    const std::time_t file_time = boost::filesystem::last_write_time(*iter, ec);
+                    if (ec.failed())
                     {
                         continue;
                     }
@@ -159,8 +159,8 @@ void LLDiskCache::purge()
         }
         if (should_remove)
         {
-            std::filesystem::remove(entry.second.second, ec);
-            if (ec.value() != 0)
+            boost::filesystem::remove(entry.second.second, ec);
+            if (ec.failed())
             {
                 LL_WARNS() << "Failed to delete cache file " << entry.second.second << ": " << ec.message() << LL_ENDL;
             }
@@ -224,23 +224,23 @@ void LLDiskCache::clearCache()
      * the component files but it's called infrequently so it's
      * likely just fine
      */
-    std::error_code ec;
+    boost::system::error_code ec;
 #if LL_WINDOWS
     std::wstring cache_path(ll_convert<std::wstring>(sCacheDir));
 #else
     std::string cache_path(sCacheDir);
 #endif
-    if (std::filesystem::is_directory(cache_path, ec) && ec.value() == 0)
+    if (boost::filesystem::is_directory(cache_path, ec) && !ec.failed())
     {
-        std::filesystem::directory_iterator iter(cache_path, ec);
-        while (iter != std::filesystem::directory_iterator() && ec.value() == 0)
+        boost::filesystem::directory_iterator iter(cache_path, ec);
+        while (iter != boost::filesystem::directory_iterator() && !ec.failed())
         {
-            if (std::filesystem::is_regular_file(*iter, ec) && ec.value() == 0)
+            if (boost::filesystem::is_regular_file(*iter, ec) && !ec.failed())
             {
                 if ((*iter).path().string().find(CACHE_FILENAME_PREFIX) != std::string::npos)
                 {
-                    std::filesystem::remove(*iter, ec);
-                    if (ec.value() != 0)
+                    boost::filesystem::remove(*iter, ec);
+                    if (ec.failed())
                     {
                         LL_WARNS() << "Failed to delete cache file " << *iter << ": " << ec.message() << LL_ENDL;
                     }
@@ -257,24 +257,24 @@ void LLDiskCache::removeOldVFSFiles()
     static const char CACHE_FORMAT[] = "inv.llsd";
     static const char DB_FORMAT[] = "db2.x";
 
-    std::error_code ec;
+    boost::system::error_code ec;
 #if LL_WINDOWS
     std::wstring cache_path(ll_convert<std::wstring>(gDirUtilp->getExpandedFilename(LL_PATH_CACHE, "")));
 #else
     std::string cache_path(gDirUtilp->getExpandedFilename(LL_PATH_CACHE, ""));
 #endif
-    if (std::filesystem::is_directory(cache_path, ec) && ec.value() == 0)
+    if (boost::filesystem::is_directory(cache_path, ec) && !ec.failed())
     {
-        std::filesystem::directory_iterator iter(cache_path, ec);
-        while (iter != std::filesystem::directory_iterator() && ec.value() == 0)
+        boost::filesystem::directory_iterator iter(cache_path, ec);
+        while (iter != boost::filesystem::directory_iterator() && !ec.failed())
         {
-            if (std::filesystem::is_regular_file(*iter, ec) && ec.value() == 0)
+            if (boost::filesystem::is_regular_file(*iter, ec) && !ec.failed())
             {
                 if (((*iter).path().string().find(CACHE_FORMAT) != std::string::npos) ||
                     ((*iter).path().string().find(DB_FORMAT) != std::string::npos))
                 {
-                    std::filesystem::remove(*iter, ec);
-                    if (ec.value() != 0)
+                    boost::filesystem::remove(*iter, ec);
+                    if (ec.failed())
                     {
                         LL_WARNS() << "Failed to delete cache file " << *iter << ": " << ec.message() << LL_ENDL;
                     }
@@ -298,23 +298,23 @@ uintmax_t LLDiskCache::dirFileSize(const std::string& dir)
      * so if performance is ever an issue, optimizing this or removing it altogether,
      * is an easy win.
      */
-    std::error_code ec;
+    boost::system::error_code ec;
 #if LL_WINDOWS
     std::wstring dir_path(ll_convert<std::wstring>(dir));
 #else
     std::string dir_path(dir);
 #endif
-    if (std::filesystem::is_directory(dir_path, ec) && ec.value() == 0)
+    if (boost::filesystem::is_directory(dir_path, ec) && !ec.failed())
     {
-        std::filesystem::directory_iterator iter(dir_path, ec);
-        while (iter != std::filesystem::directory_iterator() && ec.value() == 0)
+        boost::filesystem::directory_iterator iter(dir_path, ec);
+        while (iter != boost::filesystem::directory_iterator() && !ec.failed())
         {
-            if (std::filesystem::is_regular_file(*iter, ec) && ec.value() == 0)
+            if (boost::filesystem::is_regular_file(*iter, ec) && !ec.failed())
             {
                 if ((*iter).path().string().find(CACHE_FILENAME_PREFIX) != std::string::npos)
                 {
-                    uintmax_t file_size = std::filesystem::file_size(*iter, ec);
-                    if (ec.value() == 0)
+                    uintmax_t file_size = boost::filesystem::file_size(*iter, ec);
+                    if (!ec.failed())
                     {
                         total_file_size += file_size;
                     }