How to troubleshoot the errors if any issue comes in process builder?

Hi Saurabh ,

Use the error messages that appear in the Process Builder and the emails you receive when a process fails to help solve problems that arise when you’re working with processes. When all else fails, look at the Apex debug logs for your processes.

Common Reasons Why Processes Fail
Here are some common design problems that cause processes to fail.
Errors in the Process Builder
The API names for criteria nodes and actions are created in the background. When you create or update processes, you might see error messages that reference those names to help you identify specifically where the problem occurred.
What Happens When a Process Fails?
When a user performs an action that triggers a process (such as creating a record) and that process fails, the user sees a page with this error: “Workflow Action Failed to Trigger Flow.” In addition, the administrator who activated the process receives an email with more details.
Troubleshoot Processes with Apex Debug Logs
Use debug logs to find detailed information about your running processes after they finish running. For example, if a process doesn’t seem to trigger when a record meets the process’s criteria, or if you want to understand the sequence of processes being executed.

Thanks