Error 401 indicates that access to the requested resource requires authentication, and the provided credentials are missing, incorrect, or not accepted.
Remark
Please make sure that you have entered the correct login details!
Table of Contents
What Error 401 means
When a 401 error appears:
- the server requires login credentials
- authentication was not provided or failed
- access is restricted until valid authorization is supplied
Unlike a 403 error, a 401 specifically relates to authentication rather than general permission.
Common causes
1. Incorrect login credentials
The most frequent cause is:
- wrong username
- incorrect password
- expired credentials
2. Missing access rights
The user may:
- not belong to an authorized group
- not have permission to access the resource
3. Unsupported authentication method
Some browsers or clients may not support:
- required authentication protocols
- specific login mechanisms used by the server
4. Corrupted or misconfigured authorization data
Issues may occur if:
- password files are damaged
- authentication configuration is incorrect
- server security settings are misconfigured
Practical implications
A 401 error means the resource exists, but access is blocked until valid authentication is provided.
How to resolve it
To fix the issue:
- verify login credentials (username and password)
- ensure you are using the correct authentication method
- check if your account has access permissions
- try logging in again or resetting credentials if needed
Summary
Error 401 occurs when a request cannot be authorized due to missing or invalid credentials, requiring correct authentication before access is granted.