diff --git a/components/JsonPreview.tsx b/components/JsonPreview.tsx
index fa4f882..f6fcfe5 100644
--- a/components/JsonPreview.tsx
+++ b/components/JsonPreview.tsx
@@ -66,7 +66,7 @@ export const JsonPreview = ({
       </div>
       {show && (
         <div className="overflow-auto p-2 font-mono text-sm">
-          <pre>{JSON.stringify(content, null, 2).trim()}</pre>
+          <pre>{content ? JSON.stringify(content, null, 2).trim() : '{}'}</pre>
         </div>
       )}
     </div>
diff --git a/components/collections/actions/Action.tsx b/components/collections/actions/Action.tsx
index e56f57a..9063f00 100644
--- a/components/collections/actions/Action.tsx
+++ b/components/collections/actions/Action.tsx
@@ -337,8 +337,11 @@ export const CollectionActions = ({
   const { isLoading, mutate } = useMutation(
     async (event: FormEvent) => {
       event.preventDefault()
+      if (!wallet.isWalletConnected) {
+        throw new Error('Please connect your wallet first.')
+      }
       if (!type) {
-        throw new Error('Please select an action!')
+        throw new Error('Please select an action.')
       }
       if (minterContractAddress === '' && sg721ContractAddress === '') {
         throw new Error('Please enter minter and sg721 contract addresses!')