diff --git a/src/include/array/array_base.cc.h b/src/include/array/array_base.cc.h
index cd71cdf..dcc1779 100644
--- a/src/include/array/array_base.cc.h
+++ b/src/include/array/array_base.cc.h
@@ -181,7 +181,6 @@ namespace CNORXZ
     typename CArrayBase<T>::const_iterator CArrayBase<T>::itLexSave(const Acc& acc) const
     {
 	CXZ_ASSERT(acc.lex() < this->size(), "index out of range");
-	//CXZ_ASSERT(false, "IMPLEMENT CHECKS!!");
 	// check further compatibility of index/range format!!!
 	return begin() + acc.lex();
     }
@@ -374,7 +373,6 @@ namespace CNORXZ
     typename ArrayBase<T>::iterator ArrayBase<T>::itLexSave(const Acc& acc)
     {
 	CXZ_ASSERT(acc.lex() < this->size(), "index out of range");
-	//CXZ_ASSERT(false, "IMPLEMENT CHECKS!!");
 	// check further compatibility of index/range format!!!
 	return begin() + acc.lex();
     }
diff --git a/src/opt/hdf5/include/h5_dataset.cc.h b/src/opt/hdf5/include/h5_dataset.cc.h
index 9c4aaeb..5ce17ea 100644
--- a/src/opt/hdf5/include/h5_dataset.cc.h
+++ b/src/opt/hdf5/include/h5_dataset.cc.h
@@ -34,7 +34,7 @@ namespace CNORXZ
 		H5Sclose(memspace);
 	    }
 	    else {
-		CXZ_ERROR("IMPLEMENT!!!");
+		CXZ_ERROR("Got array type with non-trivial format; non-contiguous data formats are not supported yet!");
 	    }
 	    return *this;
 	}