diff --git a/build-scripts/build-step-arm64ec.sh b/build-scripts/build-step-arm64ec.sh
index b4d8c8def23f..21c0ef50ae7b 100644
--- a/build-scripts/build-step-arm64ec.sh
+++ b/build-scripts/build-step-arm64ec.sh
@@ -247,7 +247,7 @@ do
     rm -rf $OUTPUT_DIR/lib
     rm -rf $OUTPUT_DIR/share
     rm -rf $install_dir
-    make -j$(nproc)
+    make -j$(nproc) || exit $?
   fi
 
   if [ "$arg" == "--install" ]
@@ -257,7 +257,7 @@ do
     mkdir -p $OUTPUT_DIR/lib
     mkdir -p $OUTPUT_DIR/share
     mkdir -p $install_dir
-    make install -j$(nproc)
+    make install -j$(nproc) || exit $?
     echo "Copying files..."
     cp -r $install_dir/bin/wine* $OUTPUT_DIR/bin
     cp -r $install_dir/bin/reg* $OUTPUT_DIR/bin
diff --git a/dlls/kernelbase/process.c b/dlls/kernelbase/process.c
index 8be6c7e785be..8f8b3d2a86d5 100644
--- a/dlls/kernelbase/process.c
+++ b/dlls/kernelbase/process.c
@@ -615,6 +615,7 @@ static const WCHAR *hack_append_command_line( const WCHAR *cmd )
         {L"EverQuest 2\\LaunchPad.exe", L" --use-gl=swiftshader"},
         {L"Everquest F2P\\LaunchPad.exe", L" --use-gl=swiftshader"},
         {L"Red Tie Runner.exe", L" --use-angle=gl"},
+        {L"SocialClubHelper.exe", L" --disable-gpu --disable-gpu-compositing --disable-gpu-rasterization", "1174180"},
         {L"UnrealCEFSubProcess.exe", L" --use-gl=swiftshader", "2316580"},
         {L"UnrealCEFSubProcess.exe", L" --use-angle=d3d9", "2684500"},
     };
diff --git a/dlls/ntdll/signal_arm64ec.c b/dlls/ntdll/signal_arm64ec.c
index 3a8576d3e1bf..850af09c6b3d 100644
--- a/dlls/ntdll/signal_arm64ec.c
+++ b/dlls/ntdll/signal_arm64ec.c
@@ -1281,8 +1281,40 @@ __ASM_GLOBAL_FUNC( "#KiUserEmulationDispatcher",
 /*******************************************************************
  *		dispatch_syscall
  */
+static ULONG translate_rdr2_syscall( ULONG syscall, ULONG_PTR pc )
+{
+    static int is_rdr2 = -1;
+    WCHAR appid[8];
+    SIZE_T len;
+
+    if (syscall != 0xf2 || pc < 0x140000000ull || pc >= 0x150000000ull) return syscall;
+
+    /* RDR2's protection code bypasses ntdll and issues NtGetContextThread
+     * using the Windows 10 2009 service number 0xf2.  FEX reports it through
+     * STATUS_EMULATION_SYSCALL, but Wine 11 assigns NtGetContextThread the
+     * generated service number 0x97.  The other direct syscalls used by RDR2
+     * have explicit Windows-compatible IDs in ntdll.spec. */
+    if (is_rdr2 == -1)
+    {
+        is_rdr2 = (!RtlQueryEnvironmentVariable( NULL, L"SteamGameId", 11, appid,
+                                               ARRAY_SIZE(appid), &len ) && len == 7 &&
+                   (!wcsncmp( appid, L"1174180", 7 ) || !wcsncmp( appid, L"1404210", 7 ))) ||
+                  (!RtlQueryEnvironmentVariable( NULL, L"SteamAppId", 10, appid,
+                                               ARRAY_SIZE(appid), &len ) && len == 7 &&
+                   (!wcsncmp( appid, L"1174180", 7 ) || !wcsncmp( appid, L"1404210", 7 )));
+        if (is_rdr2) WARN( "RDR2 direct syscall at %p: 0xf2 -> %#x (NtGetContextThread).\n",
+                           (void *)pc, __id_NtGetContextThread );
+    }
+
+    /* Only translate direct calls made by the game/launcher image.  Calls
+     * through Wine's ntdll already carry Wine's own generated service IDs. */
+    return is_rdr2 ? __id_NtGetContextThread : syscall;
+}
+
 static void dispatch_syscall( ARM64_NT_CONTEXT *context )
 {
+    context->X8 = translate_rdr2_syscall( context->X8, context->Pc );
+
     if (context->X8 < __nb_syscalls)  /* syscall number in rax */
     {
         context->X0 = context->X4;  /* get first param from r10 */
diff --git a/dlls/ntdll/unix/virtual.c b/dlls/ntdll/unix/virtual.c
index 6e1697720f08..a954b6190fc0 100644
--- a/dlls/ntdll/unix/virtual.c
+++ b/dlls/ntdll/unix/virtual.c
@@ -837,6 +837,40 @@ static void reserve_area( void *addr, void *end )
 }
 
 
+/*
+ * CEF's V8 sandbox normally reserves a 1 TB placeholder.  On 39-bit ARM64
+ * hosts V8 falls back to a 128 GB partial reservation, but by the time the
+ * renderer initializes, native mappings have fragmented every suitably
+ * aligned range.  Keep one range intact from process startup.  Adding it to
+ * Wine's reserved-area list lets VirtualAlloc2 replace the PROT_NONE mapping
+ * when V8 creates its placeholder.
+ */
+static void reserve_rdr2_v8_sandbox(void)
+{
+#if defined(__aarch64__) && defined(_WIN64)
+    static const char app_id[] = "1174180";
+    const char *steam_game_id = getenv( "SteamGameId" );
+    const char *steam_app_id = getenv( "SteamAppId" );
+    void *base = (void *)0x2000000000;
+    size_t size = 0x2000000000;
+
+    if ((!steam_game_id || strcmp( steam_game_id, app_id )) &&
+        (!steam_app_id || strcmp( steam_app_id, app_id ))) return;
+    if (is_beyond_limit( base, size, host_addr_space_limit )) return;
+    if (mmap_is_in_reserved_area( base, size ) == 1) return;
+
+    if (anon_mmap_tryfixed( base, size, PROT_NONE, MAP_NORESERVE ) == base)
+    {
+        mmap_add_reserved_area( base, size );
+        FIXME( "HACK: reserved RDR2 V8 sandbox address space %p-%p.\n",
+               base, (char *)base + size );
+    }
+    else WARN( "failed to reserve RDR2 V8 sandbox address space %p-%p.\n",
+               base, (char *)base + size );
+#endif
+}
+
+
 static void mmap_init( const struct preload_info *preload_info )
 {
 #ifndef _WIN64
@@ -3957,6 +3991,9 @@ void virtual_init(void)
     size = (char *)address_space_start - (char *)0x10000;
     if (size && mmap_is_in_reserved_area( (void*)0x10000, size ) == 1)
         anon_mmap_fixed( (void *)0x10000, size, PROT_READ | PROT_WRITE, 0 );
+
+    /* Keep alloc_virtual_heap() from carving its bookkeeping data out of this area. */
+    reserve_rdr2_v8_sandbox();
 }