diff -up ./code/X3D/FIReader.cpp.irrxml ./code/X3D/FIReader.cpp
--- ./code/X3D/FIReader.cpp.irrxml	2020-01-12 06:56:40.000000000 -0500
+++ ./code/X3D/FIReader.cpp	2021-03-07 20:38:31.402545036 -0500
@@ -60,11 +60,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 #include <assimp/types.h>
 #include <assimp/MemoryIOWrapper.h>
 #include <assimp/irrXMLWrapper.h>
-#ifdef ASSIMP_USE_HUNTER
-#  include <utf8/utf8.h>
-#else
-#  include "../contrib/utf8cpp/source/utf8.h"
-#endif
+#include <utf8.h>
 #include <assimp/fast_atof.h>
 #include <stack>
 #include <map>
@@ -654,7 +650,7 @@ public:
         return currentNodeType;
     }
 
-    virtual int getAttributeCount() const /*override*/ {
+    virtual unsigned int getAttributeCount() const /*override*/ {
         return static_cast<int>(attributes.size());
     }
 
@@ -1733,7 +1729,7 @@ public:
         return reader->getNodeType();
     }
 
-    virtual int getAttributeCount() const /*override*/ {
+    virtual unsigned int getAttributeCount() const /*override*/ {
         return reader->getAttributeCount();
     }
 
diff -up ./include/assimp/irrXMLWrapper.h.irrxml ./include/assimp/irrXMLWrapper.h
--- ./include/assimp/irrXMLWrapper.h.irrxml	2020-01-12 06:56:40.000000000 -0500
+++ ./include/assimp/irrXMLWrapper.h	2021-03-07 20:38:15.760525926 -0500
@@ -133,7 +133,7 @@ public:
 
     // ----------------------------------------------------------------------------------
     //! Returns size of file in bytes
-    virtual int getSize()   {
+    virtual long getSize() const {
         return (int)data.size();
     }