diff --git a/lldb/source/Core/Module.cpp b/lldb/source/Core/Module.cpp
--- a/lldb/source/Core/Module.cpp
+++ b/lldb/source/Core/Module.cpp
@@ -1285,7 +1285,8 @@
           // those values that overwrite unspecified unknown values.
           m_arch.MergeFrom(m_objfile_sp->GetArchitecture());
         } else {
-          ReportError("failed to load objfile for {0}",
+          ReportError("failed to load objfile for {0}\nDebugging will be "
+                      "degraded for this module.",
                       GetFileSpec().GetPath().c_str());
         }
       }
diff --git a/lldb/source/Plugins/ObjectContainer/BSD-Archive/ObjectContainerBSDArchive.cpp b/lldb/source/Plugins/ObjectContainer/BSD-Archive/ObjectContainerBSDArchive.cpp
--- a/lldb/source/Plugins/ObjectContainer/BSD-Archive/ObjectContainerBSDArchive.cpp
+++ b/lldb/source/Plugins/ObjectContainer/BSD-Archive/ObjectContainerBSDArchive.cpp
@@ -540,7 +540,8 @@
           std::shared_ptr<DataBuffer> child_data_sp =
               FileSystem::Instance().CreateDataBuffer(child, file_size,
                                                       file_offset);
-          if (child_data_sp->GetByteSize() != object->file_size)
+          if (!child_data_sp ||
+              child_data_sp->GetByteSize() != object->file_size)
             return ObjectFileSP();
           lldb::offset_t data_offset = 0;
           return ObjectFile::FindPlugin(
diff --git a/lldb/test/API/functionalities/archives/Makefile b/lldb/test/API/functionalities/archives/Makefile
--- a/lldb/test/API/functionalities/archives/Makefile
+++ b/lldb/test/API/functionalities/archives/Makefile
@@ -2,7 +2,7 @@
 EXE :=  # Define a.out explicitly
 MAKE_DSYM := NO
 
-all: a.out libbar.a
+all: a.out libbar.a libfoo-thin.a
 
 a.out: main.o libfoo.a
 	$(LD) $(LDFLAGS) $^ -o $@
@@ -16,4 +16,9 @@
 	$(eval LLVM_ARFLAGS := -rcsDT)
 	$(LLVM_AR) $(LLVM_ARFLAGS) $@ $^
 
+libfoo-thin.a: a.o b.o
+	$(eval LLVM_AR := $(LLVM_TOOLS_DIR)/llvm-ar)
+	$(eval LLVM_ARFLAGS := -rcsDT)
+	$(LLVM_AR) $(LLVM_ARFLAGS) $@ $^
+
 include Makefile.rules
diff --git a/lldb/test/API/functionalities/archives/TestBSDArchives.py b/lldb/test/API/functionalities/archives/TestBSDArchives.py
--- a/lldb/test/API/functionalities/archives/TestBSDArchives.py
+++ b/lldb/test/API/functionalities/archives/TestBSDArchives.py
@@ -129,6 +129,58 @@
         ]
         self.check_frame_variable_errors(thread, error_strings)
 
+    @skipIfRemote
+    @skipUnlessDarwin
+    def test_frame_var_errors_when_thin_archive_malformed(self):
+        """
+        Create thin archive libfoo.a and make it malformed to make sure
+        we don't crash and report an appropriate error when resolving
+        breakpoint using debug map.
+        """
+        self.build()
+        exe = self.getBuildArtifact("a.out")
+        libfoo_path = self.getBuildArtifact("libfoo.a")
+        libthin_path = self.getBuildArtifact("libfoo-thin.a")
+        objfile_a = self.getBuildArtifact("a.o")
+        # Replace the libfoo.a file with a thin archive containing the same
+        # debug information (a.o, b.o). Then remove a.o from the file system
+        # so we force an error when we set a breakpoint on a() function.
+        # Since the a.o is missing, the debug info won't be loaded and we
+        # should see an error when trying to break into a().
+        os.remove(libfoo_path)
+        shutil.copyfile(libthin_path, libfoo_path)
+        os.remove(objfile_a)
+
+        self.runCmd("file " + exe, CURRENT_EXECUTABLE_SET)
+        # We won't be able to see source file
+        self.expect(
+            "b a",
+            substrs=["Breakpoint 1: where = a.out`a, address ="],
+        )
+        # Break at a() should fail
+        (target, process, thread, bkpt) = lldbutil.run_to_name_breakpoint(
+            self, "a", bkpt_module=exe
+        )
+        error_strings = [
+            '"a.o" object from the "',
+            "libfoo.a\" archive: either the .o file doesn't exist in the archive or the modification time (0x",
+            ") of the .o file doesn't match",
+        ]
+        self.check_frame_variable_errors(thread, error_strings)
+
+        # Break at b() should succeed
+        (target, process, thread, bkpt) = lldbutil.run_to_name_breakpoint(
+            self, "b", bkpt_module=exe
+        )
+        self.expect(
+            "thread list",
+            STOPPED_DUE_TO_BREAKPOINT,
+            substrs=["stopped", "stop reason = breakpoint"],
+        )
+        self.expect(
+            "frame variable", VARIABLES_DISPLAYED_CORRECTLY, substrs=["(int) arg = 2"]
+        )
+
     @skipIfRemote
     @skipUnlessDarwin
     def test_frame_var_errors_when_mtime_mistmatch_for_object_in_archive(self):