diff --git a/package-lock.json b/package-lock.json
index 881f18f..a3e69e0 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -16689,8 +16689,7 @@
     "uuid": {
       "version": "8.3.2",
       "resolved": "https://registry.npmjs.org/uuid/-/uuid-8.3.2.tgz",
-      "integrity": "sha512-+NYs2QeMWy+GWFOEm9xnn6HCDp0l7QBD7ml8zLUmJ+93Q5NF0NocErnwkTkXVFNiX3/fpC6afS8Dhb/gz7R7eg==",
-      "optional": true
+      "integrity": "sha512-+NYs2QeMWy+GWFOEm9xnn6HCDp0l7QBD7ml8zLUmJ+93Q5NF0NocErnwkTkXVFNiX3/fpC6afS8Dhb/gz7R7eg=="
     },
     "uuid4": {
       "version": "1.1.4",
diff --git a/package.json b/package.json
index 755c8f6..c677212 100644
--- a/package.json
+++ b/package.json
@@ -23,6 +23,7 @@
     "react-scripts": "4.0.1",
     "react-select-search": "^2.2.4",
     "react-table": "^7.6.3",
+    "uuid": "^8.3.2",
     "web-vitals": "^0.2.4"
   },
   "scripts": {
diff --git a/src/components/ConfusionMatrix/Table.jsx b/src/components/ConfusionMatrix/Table.jsx
index 1b2563f..8d6dc4c 100644
--- a/src/components/ConfusionMatrix/Table.jsx
+++ b/src/components/ConfusionMatrix/Table.jsx
@@ -13,6 +13,7 @@ import {
   ModalFooter,
   useDisclosure,
 } from '@chakra-ui/react';
+import { v4 as uuidv4 } from 'uuid';
 import { Table, Thead, Tbody, Tfoot, Tr, Th, Td, TableCaption } from '@chakra-ui/react';
 import { predict } from '../../utils/predict';
 
@@ -34,7 +35,7 @@ function TableComponent({ confusionMatrix, headers }) {
           <Th></Th>
           <Th></Th>
           {headers.map(x => (
-            <Th key={Math.random() + 5}>{x}</Th>
+            <Th key={uuidv4()}>{x}</Th>
           ))}
         </Tr>
       </Thead>
@@ -42,7 +43,7 @@ function TableComponent({ confusionMatrix, headers }) {
         {confusionMatrix.map((x, idx) => {
           console.log(x, idx);
           return (
-            <Tr key={Math.random() + 51}>
+            <Tr key={uuidv4()}>
               {idx === 0 ? (
                 <Th
                   rowSpan={confusionMatrix.length}
@@ -60,7 +61,7 @@ function TableComponent({ confusionMatrix, headers }) {
               )}
               <Th>{headers[idx]}</Th>
               {x.map(y => (
-                <Td key={Math.random() + 511}>{y}</Td>
+                <Td key={uuidv4()}>{y}</Td>
               ))}
             </Tr>
           );
diff --git a/src/components/Crossvalidator/Crossvalidator.jsx b/src/components/Crossvalidator/Crossvalidator.jsx
index 2b5bc14..3a18413 100644
--- a/src/components/Crossvalidator/Crossvalidator.jsx
+++ b/src/components/Crossvalidator/Crossvalidator.jsx
@@ -1,5 +1,6 @@
 import { Box, SimpleGrid, Stack, StackDivider } from '@chakra-ui/react';
 import React, { useState, useMemo } from 'react';
+import { v4 as uuidv4 } from 'uuid';
 import { mergeChunksWithoutChosen } from '../../utils/cross-valid';
 import ConfusionMatrix from '../ConfusionMatrix';
 import SmallConfusionMatrix from './SmallConfusionMatrix';
@@ -23,29 +24,31 @@ import TreePrinter from '../TreePrinter';
  * @param {Array} props.chunks
  * @param {Object} props.treeModels
 
- * @returns
+ * @return
  */
 function CrossValidator({ builder, chunks, treeModels }) {
-  const [allAccuracy, setAllAccuracy] = useState([]);
-  const AllAccuracyObject = useMemo(() => Object.values(allAccuracy), [allAccuracy]);
+  const [allAccuracy, setAllAccuracy] = useState({});
 
   const [selectedTree, setSelectedTree] = useState(null);
   const [selectedIndex, setSelectedIndex] = useState(0);
-  const [acc, setAcc] = useState({});
 
-  function updateAccuracy(e, i) {
-    console.log('Accuracy');
-    console.log(e, i);
-    if (allAccuracy.length != chunks.length) {
-      //setAllAccuracy([...allAccuracy, e]);
+  useEffect(() => {
+    console.log(JSON.parse(JSON.stringify(allAccuracy)));
+  }, [allAccuracy]);
+
+  function updateAccuracy({ train, test, index }) {
+    if (allAccuracy[index]?.train === train && allAccuracy[index]?.test === test) {
+      return;
     }
-    // setAllAccuracy(prevState => ({
-    //   ...prevState,
-    //   [i]: e,
-    // }));
-    console.log(allAccuracy);
+    setAllAccuracy(m => ({ ...m, [index]: { train, test } }));
   }
 
+  const [trainAcc, testAcc] = useMemo(() => {
+    const items = Object.values(allAccuracy);
+    const avg = key => items.reduce((acc, x) => acc + x[key], 0) / items.length;
+    return [avg('train'), avg('test')];
+  }, [allAccuracy]);
+
   // useEffect(() => {
   //   function getAccuracy() {
   //     const values = Object.values(AllAccuracyObject);
@@ -88,7 +91,7 @@ function CrossValidator({ builder, chunks, treeModels }) {
       >
         {treeModels.map((x, i) => (
           <SampleTreeItem
-            key={Math.random() + i}
+            key={uuidv4()}
             builder={builder}
             chunks={chunks}
             item={x}
@@ -99,13 +102,8 @@ function CrossValidator({ builder, chunks, treeModels }) {
         ))}
       </SimpleGrid>
       <div>
-        <p>
-          Training accuracy:{' '}
-          {allAccuracy?.reduce((partialSum, a) => partialSum + a.training, 0) / allAccuracy.length}
-        </p>
-        <p>
-          Test accuracy: {allAccuracy?.reduce((partialSum, a) => partialSum + a.test, 0) / allAccuracy.length}
-        </p>
+        <p>Training accuracy: {trainAcc}</p>
+        <p>Test accuracy: {testAcc}</p>
       </div>
       <div>
         <p>Tree {selectedIndex + 1}</p>
@@ -118,7 +116,7 @@ function CrossValidator({ builder, chunks, treeModels }) {
       </div>
       {/* <div>
         {treeModels.map((x, i) => (
-          <p key={Math.random() + 5}>
+          <p key={uuidv4()}>
             Tree {i}{' '}
             <ConfusionMatrix
               tree={x}
@@ -150,15 +148,23 @@ export default CrossValidator;
 function SampleTreeItem({ builder, chunks, item, index, onGetResults, onSelectedTree }) {
   const [trainAcc, setTrainAcc] = useState(null);
   const [testAcc, setTestAcc] = useState(null);
-  const [acc, setAcc] = useState({
-    training: null,
-    test: null,
-  });
+  const [data, setData] = useState(null);
+
+  useEffect(() => {
+    setData(mergeChunksWithoutChosen(chunks, index));
+  }, []);
 
   function clickSelectTree(tree, index) {
     onSelectedTree(tree, index);
   }
 
+  useEffect(() => {
+    if (trainAcc === null || testAcc === null) {
+      return;
+    }
+    onGetResults({ train: trainAcc, test: testAcc, index });
+  }, [trainAcc, testAcc]);
+
   function getTreningAccuracy(value) {
     setTrainAcc(value);
     //onGetResults({ ...acc, training: value });
@@ -169,34 +175,22 @@ function SampleTreeItem({ builder, chunks, item, index, onGetResults, onSelected
     //onGetResults({ ...acc, test: value });
   }
 
-  useEffect(() => {
-    // console.log('usseeffececct', acc);
-    // if (acc.training != null && acc.test != null) {
-    //   onGetResults(acc);
-    // }
-  }, [acc, onGetResults]);
-
   return (
-    <Box
-      key={Math.random() + 5}
-      padding={1}
-      width={220}
-      height={55}
-      border={'1px solid black'}
-      borderRadius={5}
-    >
+    <Box key={uuidv4()} padding={1} width={220} height={55} border={'1px solid black'} borderRadius={5}>
       <p className="sampleTreeItem" style={{ textAlign: 'left' }} onClick={e => clickSelectTree(item, index)}>
         <b>Tree {index + 1}</b>
       </p>
       <SimpleGrid columns={2} spacing={1}>
-        <SmallConfusionMatrix
-          tree={item}
-          data={mergeChunksWithoutChosen(chunks, index)}
-          allClasses={builder.allClasses}
-          categoryAttr={builder.categoryAttr}
-          onChange={getTreningAccuracy}
-          type={'Trening'}
-        />
+        {data && (
+          <SmallConfusionMatrix
+            tree={item}
+            data={data}
+            allClasses={builder.allClasses}
+            categoryAttr={builder.categoryAttr}
+            onChange={getTreningAccuracy}
+            type={'Trening'}
+          />
+        )}
         <SmallConfusionMatrix
           tree={item}
           data={chunks[index]}
diff --git a/src/components/Navigation/index.jsx b/src/components/Navigation/index.jsx
index 7be52ba..b023e03 100644
--- a/src/components/Navigation/index.jsx
+++ b/src/components/Navigation/index.jsx
@@ -1,4 +1,4 @@
-import React, { useState } from 'react';
+import React, { useMemo, useState } from 'react';
 import '../../css/main.scss';
 import '../../css/inputs.scss';
 import { Checkbox, Collapse, FormHelperText, Icon, useDisclosure, Wrap, WrapItem } from '@chakra-ui/react';
@@ -36,6 +36,7 @@ function Navigation({ onPrepareConfig, setHeaders, onCrossValidation }) {
   const [folds, setFolds] = useState(10);
   const { attributes: options, onAttributesChange } = useAttributesContext();
   //const { attributes: ignoredAttributes, onIgnoredChange } = useIgnoredContext();
+  const optionsViewModel = useMemo(() => options.map(model => ({ ...model, key: model.value })), [options]);
   const { isLoading } = useLoadingContext();
 
   function handleSelectDecision(value) {
@@ -196,7 +197,7 @@ function Navigation({ onPrepareConfig, setHeaders, onCrossValidation }) {
                   placeholder="Select algorithm"
                   onChange={handleSetAlgorithm}
                   value={algorithm}
-                  options={['c45', 'tsp', 'tspw'].map(v => ({ value: v, name: v.toUpperCase() }))}
+                  options={['c45', 'tsp', 'tspw'].map(v => ({ value: v, name: v.toUpperCase(), key: v }))}
                   multiple={true}
                   closeOnSelect={false}
                 />
@@ -216,7 +217,7 @@ function Navigation({ onPrepareConfig, setHeaders, onCrossValidation }) {
                 <SearchBar
                   placeholder="Select decision attribute"
                   onChange={handleSelectDecision}
-                  options={options}
+                  options={optionsViewModel}
                   multiple={false}
                   closeOnSelect={true}
                   value={decisionAttribute}
@@ -237,7 +238,7 @@ function Navigation({ onPrepareConfig, setHeaders, onCrossValidation }) {
                 <SearchBar
                   placeholder="Select ignore attributes"
                   onChange={handleSelectIgnore}
-                  options={options}
+                  options={optionsViewModel}
                   multiple={true}
                   closeOnSelect={false}
                   value={ignoredAttributes}
diff --git a/src/components/Node/DataViewer/index.jsx b/src/components/Node/DataViewer/index.jsx
index 8bd966c..104829d 100644
--- a/src/components/Node/DataViewer/index.jsx
+++ b/src/components/Node/DataViewer/index.jsx
@@ -17,6 +17,7 @@ import {
   Tooltip,
   useDisclosure,
 } from '@chakra-ui/react';
+import { v4 as uuidv4 } from 'uuid';
 import { CgDatabase } from 'react-icons/cg';
 import { AiOutlineArrowDown, AiOutlineArrowUp } from 'react-icons/ai';
 import DataViewerTable from './DataViewerTable';
@@ -49,7 +50,7 @@ function DataViewer({ node, side, onChange, hide }) {
   }
 
   const NodeCountClass = Object.entries(nodeCountness).map(v => (
-    <Tag key={Math.random() + 10} ml={3} colorScheme="blackAlpha">
+    <Tag key={uuidv4()} ml={3} colorScheme="blackAlpha">
       {v[0]} ({v[1]})
     </Tag>
   ));