diff --git a/src/blockchain/contract.js b/src/blockchain/contract.js
index b304090..00b1ecf 100644
--- a/src/blockchain/contract.js
+++ b/src/blockchain/contract.js
@@ -28,7 +28,7 @@ export async function queryHelperContract(helper, provider) {
 
 
 // do not supply extensions with name or file: e.g.
-// use newContract(addr, 'IVaultLogic', provider, 'IVault') to get the ABI from IVault.sol/IVaultLogic.json
+// use newContract(addr, 'IVaultImpl', provider, 'IVault') to get the ABI from IVault.sol/IVaultImpl.json
 export async function newContract(addr, name, provider) {
     const abi = await abiCache.get(name)
     return new ethers.Contract(addr, abi, provider)
diff --git a/src/blockchain/wallet.js b/src/blockchain/wallet.js
index d367b4c..5e052ef 100644
--- a/src/blockchain/wallet.js
+++ b/src/blockchain/wallet.js
@@ -493,14 +493,13 @@ export async function detectUpgrade() {
         newContract(info.factory, 'IVaultFactory', provider),
         newContract(s.vault, 'IVault', provider),
     ])
-    const vaultLogic = await vault.logic()
-    const latestLogic = await factory.logic()
-    // const [vaultLogic, latestLogic] = await Promise.all( vault.logic(), factory.logic() )
-    console.log('vaultLogic / latestLogic', vaultLogic, latestLogic)
-    if ( vaultLogic !== latestLogic ) {
-      s.upgrade = latestLogic
-      const logic = await newContract(latestLogic, 'IVault', provider)
-      const version = await logic.version()
+    const vaultImpl = await vault.impl()
+    const latestImpl = await factory.impl()
+    console.log('vaultImpl / latestImpl', vaultImpl, latestImpl)
+    if ( vaultImpl !== latestImpl ) {
+      s.upgrade = latestImpl
+      const impl = await newContract(latestImpl, 'IVault', provider)
+      const version = await impl.version()
       console.log(`found vault version ${version}`)
       return version
     }
@@ -512,10 +511,10 @@ export async function detectUpgrade() {
 }
 
 
-function upgradeSender(vault, logic) {
+function upgradeSender(vault, impl) {
   return async function (signer) {
     const v = await vaultContract(vault, signer)
-    v.upgrade(logic)
+    v.upgrade(impl)
   }
 }
 
@@ -524,7 +523,7 @@ function upgradeError(e) {
   console.error('error while upgrading vault', e)
 }
 
-export async function upgradeVault(vault, logic) {
-  pendTransaction(upgradeSender(vault, logic), upgradeError)
+export async function upgradeVault(vault, impl) {
+  pendTransaction(upgradeSender(vault, impl), upgradeError)
 }
 
diff --git a/src/charts/datafeed.js b/src/charts/datafeed.js
index 0298f75..a21e153 100644
--- a/src/charts/datafeed.js
+++ b/src/charts/datafeed.js
@@ -595,6 +595,7 @@ export const DataFeed = {
 
 
 	poolCallback(chainId, poolPeriod, ohlcs) {
+		if (!ohlcs || ohlcs.length===0) return
 		const key = `${chainId}|${poolPeriod}`;
 		const bars = []
 		for (const ohlc of ohlcs) {
diff --git a/src/common.js b/src/common.js
index 7ecf8fd..47f9a29 100644
--- a/src/common.js
+++ b/src/common.js
@@ -123,11 +123,10 @@ export class AbiURLCache extends AsyncURLCache {
 
 const files = {
     // If a contract is in a file different than its name, put the exception here
-    // 'IVaultLogic' : 'IVault', // for example
-    'IVaultLogic' : 'IVault', // for example
+    // 'IVaultImpl' : 'IVault',  // for example
 }
 
 export function abiPath(name) {
     const file = files[name]
-    return `${file?file:name}.sol/${name}.json`
+    return `${file??name}.sol/${name}.json`
 }