There are several common issues that may arise when using nested loops in Vue.js, such as infinite rendering, missing data, or undefined variables. Here are some troubleshooting steps you can take:

1. Check the Data Binding: Ensure that the data used in your loop is correctly bound to the component's properties. Use v-bind (:) to bind the data to the components so that Vue can track changes and update the view accordingly.

2. Use Key Attribute: When you use loops in Vue.js, it's important to include a unique key attribute for each element within your loop. This helps Vue keep track of elements and their positions, which can improve performance and prevent unwanted side effects.

3. Check Your Data Structure: Ensure that the data structure you are using for nested loops is correct. If the nested object or array is not properly structured, it may cause errors when rendering your components.

4. Use V-If Conditional Rendering: Sometimes, if conditions can lead to infinite looping issues in Vue.js. Ensure that you're not using v-if on elements that are being rendered within a loop. Instead, consider using v-show or a computed property to conditionally display your content.

5. Remove Unused Variables: Sometimes, unused variables can cause errors when rendering nested loops in Vue.js. Be sure to use only the variables you need for your loop and remove any other unnecessary variables.

6. Use Watch Properties: If you're using data that changes frequently within a loop, consider using watch properties to ensure that your loop is updated correctly. This can help prevent infinite loops and improve performance.

7. Clear Unused Code: Be sure to clear any unused code within your Vue.js components that may cause errors or unwanted behavior. Remove any unnecessary data bindings or computed properties, and make sure that your code is well-structured and readable.