diff --git a/engine/CMakeLists.txt b/engine/CMakeLists.txt
index 0202e810fd..200c9cb565 100644
--- a/engine/CMakeLists.txt
+++ b/engine/CMakeLists.txt
@@ -178,6 +178,8 @@ ENDIF(NOT POW_FUNCTION_EXISTS AND NOT NEED_LINKING_AGAINST_LIBM)
 IF (NOT CMAKE_BUILD_TYPE)
     SET(CMAKE_BUILD_TYPE "RelWithDebInfo" CACHE STRING "Release, RelWithDebInfo, Debug, Profiler" FORCE )
 ENDIF (NOT CMAKE_BUILD_TYPE)
+MESSAGE("** Build Type: ${CMAKE_BUILD_TYPE}")
+
 
 #IF (NOT BUILD_OPT)
 #    SET(BUILD_OPT -O2 CACHE STRING "-O0, -O1, -O2, -O3, -Os, -Ofast" FORCE )
@@ -296,10 +298,12 @@ add_compile_options("$<$<CXX_COMPILER_ID:MSVC>:/FI${Vega_Strike_BINARY_DIR}/conf
         "$<$<AND:$<CXX_COMPILER_ID:MSVC>,$<CONFIG:Debug>>:/Z7>"
         )
 add_link_options("$<$<CXX_COMPILER_ID:MSVC>:/DEBUG>")
+# for DEBUG remove all optimizations
 add_compile_options("$<$<OR:$<CXX_COMPILER_ID:GNU>,$<CXX_COMPILER_ID:Clang>,$<CXX_COMPILER_ID:AppleClang>>:-pipe>"
         "$<$<OR:$<CXX_COMPILER_ID:GNU>,$<CXX_COMPILER_ID:Clang>,$<CXX_COMPILER_ID:AppleClang>>:-Wall>"
         "$<$<OR:$<CXX_COMPILER_ID:GNU>,$<CXX_COMPILER_ID:Clang>,$<CXX_COMPILER_ID:AppleClang>>:-fvisibility=hidden>"
-        "$<$<AND:$<OR:$<CXX_COMPILER_ID:GNU>,$<CXX_COMPILER_ID:Clang>,$<CXX_COMPILER_ID:AppleClang>>,$<OR:$<CONFIG:Debug>,$<CONFIG:Profiler>,$<CONFIG:RelWithDebInfo>>>:-Og>"
+        "$<$<AND:$<OR:$<CXX_COMPILER_ID:GNU>,$<CXX_COMPILER_ID:Clang>,$<CXX_COMPILER_ID:AppleClang>>,$<CONFIG:Debug>>:-O0>"
+        "$<$<AND:$<OR:$<CXX_COMPILER_ID:GNU>,$<CXX_COMPILER_ID:Clang>,$<CXX_COMPILER_ID:AppleClang>>,$<OR:$<CONFIG:Profiler>,$<CONFIG:RelWithDebInfo>>>:-Og>"
         "$<$<AND:$<OR:$<CXX_COMPILER_ID:GNU>,$<CXX_COMPILER_ID:Clang>,$<CXX_COMPILER_ID:AppleClang>>,$<OR:$<CONFIG:Debug>,$<CONFIG:RelWithDebInfo>>>:-g3>"
         "$<$<AND:$<OR:$<CXX_COMPILER_ID:GNU>,$<CXX_COMPILER_ID:Clang>,$<CXX_COMPILER_ID:AppleClang>>,$<CONFIG:Profiler>>:-pg>"
         "$<$<AND:$<OR:$<CXX_COMPILER_ID:GNU>,$<CXX_COMPILER_ID:Clang>,$<CXX_COMPILER_ID:AppleClang>>,$<CONFIG:Profiler>>:-g2>"
diff --git a/engine/src/cmd/json.cpp b/engine/src/cmd/json.cpp
index e5710b0515..cb576a1d68 100644
--- a/engine/src/cmd/json.cpp
+++ b/engine/src/cmd/json.cpp
@@ -5,6 +5,8 @@
 #include "json.h"
 #include <string.h>
 
+#include "vs_logging.h"
+
 /*! \brief Checks for an empty string
  *
  * @param str The string to check
@@ -388,6 +390,12 @@ std::vector<std::string> json::parsing::parse_array(const char *input)
     // Initalize the result
     std::vector<std::string> result;
 
+    if (input != nullptr) {
+        VS_LOG_AND_FLUSH(debug, boost::format("JSON Data: %s") % input);
+    } else {
+        VS_LOG_AND_FLUSH(debug, "Invalid JSON Input - NULL Pointer");
+    }
+
     const char *index = json::parsing::tlws(input);
     if (*index != '[') throw json::parsing_error("Input was not an array");
     index++;
diff --git a/engine/src/cmd/upgradeable_unit.cpp b/engine/src/cmd/upgradeable_unit.cpp
index 891b485cab..210b3fceb4 100644
--- a/engine/src/cmd/upgradeable_unit.cpp
+++ b/engine/src/cmd/upgradeable_unit.cpp
@@ -38,6 +38,7 @@
 #include "unit_generic.h"
 #include "weapon_info.h"
 #include "vega_cast_utils.h"
+#include "vs_logging.h"
 
 std::vector<std::string> ParseUnitUpgrades(const std::string &upgrades) {
     if(upgrades.size() == 0) {
@@ -141,6 +142,14 @@ bool UpgradeableUnit::UpgradeMounts(const Unit *up,
         return true;
     }
 
+    // there needs to be some mounts to be able to mount to
+    if (num_mounts == 0) {
+        // would be nice to make this more meaningful but that's a little harder given
+        // the casting of `unit` from `this`.
+        VS_LOG(debug, "No mounts to attach to.");
+        return false;
+    }
+
     int j = mountoffset;
     int i = 0;
     bool cancompletefully = true;
diff --git a/engine/src/gfx/mesh_gfx.cpp b/engine/src/gfx/mesh_gfx.cpp
index d9f8ba0018..23edb8db44 100644
--- a/engine/src/gfx/mesh_gfx.cpp
+++ b/engine/src/gfx/mesh_gfx.cpp
@@ -438,15 +438,41 @@ Mesh::~Mesh() {
         vector<Mesh *> *hashers = bfxmHashTable.Get(hash_name);
         vector<Mesh *>::iterator finder;
         if (hashers) {
-            for (size_t i = hashers->size() - 1; i >= 0; --i) {
-                if (hashers->at(i) == this) {
-                    hashers->erase(hashers->begin() + i);
+            // the foollowing loop has several tricks to it:
+            // 1. `std::vector::erase()` can take an interator and remove it from the vector; but invalidates
+            //      the iterator in the process
+            // 2. To overcome the invalid iterator issue, the next previous iterator is cached
+            // 3. In the case that the previous iterator would be invalid (e.g it's at the start) then it needs
+            //      to restart the loop without the loop conditions, therefore a simple GOTO is used instead to
+            //      avoid the incrementing the iterator so that values are not skipped
+            // A reverse iterator could kind of help this; however, `std::vector::erase` unfortunately
+            // does not work on reverse iterators.
+            for (auto hashItem = hashers->begin(); hashItem != hashers->end(); ++hashItem) {
+retryEraseItem:
+                if (*hashItem == this) {
+                    bool resetIter = false;
+                    auto cachedHashItem = hashers->begin();
+                    if (hashItem != hashers->begin()) {
+                        cachedHashItem = hashItem - 1;
+                    } else {
+                        resetIter = true;
+                        cachedHashItem = hashItem + 1;
+                    }
+                    hashers->erase(hashItem);
                     if (hashers->empty()) {
                         bfxmHashTable.Delete(hash_name);
                         delete hashers;
                         hashers = nullptr;
                         break;
                     }
+
+                    if (resetIter) {
+                        hashItem = hashers->begin();
+                        // a necessary use of Goto as we do not want to use ++hashItem
+                        goto retryEraseItem;
+                    } else {
+                        hashItem = cachedHashItem;
+                    }
                 }
             }
         }
diff --git a/engine/vcpkg.json b/engine/vcpkg.json
index 3d66e9e900..4f949e94b8 100644
--- a/engine/vcpkg.json
+++ b/engine/vcpkg.json
@@ -27,6 +27,7 @@
             "version>=": "1.1.1m"
         },
         "sdl1",
+        "sdl2",
         "zlib"
     ]
 }