*、Error: Can't set headers after they are sent.
The first type: node.js adopts an asynchronous response mechanism, so if res.send() occurs multiple times, the previous response stream will be closed, causing an exception The solution is to comment out the redundant res.send(); The second: Track the specific code and setHeader(); Comment the line with the error, this method is potentially dangerous, choose carefully
*、Failed to lookup view "/searchUser.ejs" in views directory
The routing is abnormal, there is a problem with the path writing, check the specific jump instructions of the code