diff --git a/lib_com/bitstream.c b/lib_com/bitstream.c
old mode 100644
new mode 100755
index 04fdb8fe0bb9ba6f01616a22bae4e95362ad2708..dcd1b71684cdef22049e8a112685bb52dab24e4f
--- a/lib_com/bitstream.c
+++ b/lib_com/bitstream.c
@@ -772,7 +772,11 @@ int16_t get_ivas_max_num_indices_metadata(                                /* o
         }
         else if ( ivas_total_brate <= IVAS_256k )
         {
+#ifdef FIX_483b
+            return 1050;
+#else
             return 1000;
+#endif
         }
         else if ( ivas_total_brate <= IVAS_384k )
         {
diff --git a/lib_com/options.h b/lib_com/options.h
index 72332841b3a6f77bc673e4a942678f17ec0b407b..dccc11cf17282a074448861f9cd38c1a667720da 100755
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -218,6 +218,9 @@
 
 #define FIX_481_UNUSED_VARIABLES                        /* Nokia: Fix issue #481: Unused debug variables */
 
+#define FIX_483                                         /* FhG: fix issue 483, division by zero in nois_est */
+#define FIX_483b                                        /* FhG: fix issue 483, uninitialized values in ivas_mct_core_enc */
+
                                                         /* ################## End DEVELOPMENT switches ######################### */
 /* clang-format on */
 
diff --git a/lib_com/rom_com.c b/lib_com/rom_com.c
old mode 100644
new mode 100755
diff --git a/lib_enc/ivas_mct_core_enc.c b/lib_enc/ivas_mct_core_enc.c
old mode 100644
new mode 100755
index 3bd05fca9273da133393856ddd848a8829dd34a9..48a7abc42f48ce40c9d1804b2551036cd98474a0
--- a/lib_enc/ivas_mct_core_enc.c
+++ b/lib_enc/ivas_mct_core_enc.c
@@ -264,6 +264,11 @@ void ivas_mct_core_enc(
 
             sp_aud_decision0[i] = hCPE[cpe_id]->hCoreCoder[0]->sp_aud_decision0;
 
+#ifdef FIX_483b
+            sts[i]->hTcxEnc->tns_ms_flag[0] = 0;
+            sts[i]->hTcxEnc->tns_ms_flag[1] = 0;
+#endif
+
             i++;
         }
     }
@@ -339,7 +344,11 @@ void ivas_mct_core_enc(
 
         for ( n = 0; n < nSubframes; n++ )
         {
+#ifdef FIX_483b
+            if ( sts[ch]->hTcxEnc->tns_ms_flag[n] )
+#else
             if ( !sts[ch]->hTcxEnc->fUseTns[n] /*!sts[0]->fUseTns[n] && !sts[1]->fUseTns[n]*/ )
+#endif
             {
                 /* power spectrum: MDCT^2 + MDST^2 */
                 for ( i = 0; i < L_subframeTCX; i++ )
diff --git a/lib_enc/ivas_stereo_mdct_stereo_enc.c b/lib_enc/ivas_stereo_mdct_stereo_enc.c
old mode 100644
new mode 100755
index 4ef24de8a191368165a8406f556121d047f5be93..138c9436d6664a3c16dce55a5761fcd866156e0e
--- a/lib_enc/ivas_stereo_mdct_stereo_enc.c
+++ b/lib_enc/ivas_stereo_mdct_stereo_enc.c
@@ -430,6 +430,10 @@ void stereo_coder_tcx(
 
                 if ( !sts[0]->hTcxEnc->fUseTns[k] && !sts[1]->hTcxEnc->fUseTns[k] )
                 {
+#ifdef FIX_483b
+                    sts[0]->hTcxEnc->tns_ms_flag[k] = 1;
+                    sts[1]->hTcxEnc->tns_ms_flag[k] = 1;
+#endif
                     ms_inv_mask_processing( hStereoMdct, sts, ms_mask, k, mdst_spectrum[0][k], mdst_spectrum[1][k], inv_mdst_spectrum[0][k], inv_mdst_spectrum[1][k], -1 );
                     ms_processing( hStereoMdct, sts, ms_mask, k, mdst_spectrum[0][k], mdst_spectrum[1][k], sfbConf->sfbCnt );
                 }
diff --git a/lib_enc/nois_est.c b/lib_enc/nois_est.c
index 50dab410281d7ae6e98b803c6a792242b37f9981..bf506cd9db8d412e8f22fcc5d9d10d2bc4f691c0 100644
--- a/lib_enc/nois_est.c
+++ b/lib_enc/nois_est.c
@@ -378,6 +378,20 @@ void noise_est(
     {
         if ( st->hSpMusClas != NULL )
         {
+#ifdef FIX_483
+            float E;
+
+            E = mean( lf_E, 8 );
+            if ( E < 1.0f )
+            {
+                st->hSpMusClas->ener_RAT = 0.f;
+            }
+            else
+            {
+                st->hSpMusClas->ener_RAT = 10.0f * (float) log10( E );
+                st->hSpMusClas->ener_RAT /= ( Etot + 0.01f );
+            }
+#else
             st->hSpMusClas->ener_RAT = 10.0f * (float) log10( mean( lf_E, 8 ) );
             st->hSpMusClas->ener_RAT /= ( Etot + 0.01f );
 
@@ -385,6 +399,7 @@ void noise_est(
             {
                 st->hSpMusClas->ener_RAT = 0.0f;
             }
+#endif
 
             if ( st->hSpMusClas->ener_RAT > 1.0 )
             {
diff --git a/lib_enc/stat_enc.h b/lib_enc/stat_enc.h
old mode 100644
new mode 100755
index 77c0ea3d34eb98386bb3a23a3128044af9cc7859..1a5c893dbd9816aa0c903d9bf64c86a0656ac730
--- a/lib_enc/stat_enc.h
+++ b/lib_enc/stat_enc.h
@@ -1121,6 +1121,10 @@ typedef struct tcx_enc_structure
     float *acelp_zir;
     float tcx_target_bits_fac;
 
+#ifdef FIX_483b
+    int16_t tns_ms_flag[2];
+#endif
+
 } TCX_ENC_DATA, *TCX_ENC_HANDLE;
 /*----------------------------------------------------------------------------------*
  *