What is a 401 error?

A "401 Unauthorized Error" is an "HTTP response status code" which indicates that the sent request could not be authenticated or verified by the requester.

In case of a 401 report, the server could not confirm that you are authorized to access the requested file or address. It may have been provided (e.g. wrong password), or your browser does not understand how to provide the mandatory data. The 401 status code is similar to a 403 status code, but they are different.

Client side or server side?

The status code 401 in question falls into the category for "client error responses", or error messages that may occur on the end user's side. This does not necessarily mean that there is a problem on the client side, but simply means that access cannot/should not be granted.

Cause

The cause of a 401 status code can be one of the following:

The applicant has duly completed the authentication, however, the server has rejected this authentication attempt due to possible incorrect authentication data

The requestor has not provided any information to authenticate the request.

The applicant is banned from the environment and will also not have the ability to authenticate themselves.

Banning a requestor from that location can be done by blocking the requester's ip address.

Dissolve

You can solve a 401 status code by checking a number of points:

Check if you are requesting the correct url/location. You may have made a type error in your url or received a wrong url/location that therefore has a security feature, while it may not have been the intention to access this secure environment.

Clearing cookies and caches can also sometimes solve the problem. Your internet browser may have cached an authentication attempt. This will make your internet browser try to authenticate with the requested location every time. This authentication attempt can then possibly be made with incorrect or old data that is remembered in the cache.

If possible, it can sometimes help to log in again in the relevant environment. It can happen that when you are logged in, a session of the user is not processed properly. When you log in again, the session will be created and processed again. In this way it may be possible to visit the requested url/location again.

.htaccess

If you have control over the relevant document/location/url and you have not set up this authentication. Then you can often disable this by removing the authentication rules in the .htaccess of your site.

The lines in the .htaccess can look like this:

AuthName "Secure Environment" AuthUserFile /path/to/your/dir/.htpasswd AuthGroupFile /dev/null AuthType Basic

require valid user

When you remove these lines from the .htaccess, the authentication will also disappear for the document in question.