You open your laptop between classes, type in the address of the CESI ENT, and the page loops endlessly on the Microsoft authentication screen without ever loading. This scenario happens often, and the cause is rarely a server issue. Most of the time, it’s a browser setting or a forgotten multifactoring authentication step that blocks access. This guide focuses on the actual friction points, device by device.
Cookies and browser cache: the primary cause of blockage on CESI ENT
Even before discussing username or password, we encounter a problem that most guides overlook. Several university ENTs, including CESI’s, redirect to a CAS (Central Authentication Service) portal that deposits session cookies. If the browser blocks third-party cookies, the redirection loops endlessly and you never get past the login page.
On mobile, this is even more common. Safari on iPhone by default activates cross-site tracking prevention, which can prevent the authentication cookie from being set correctly. On Chrome Android, simplified browsing mode or an integrated ad blocker produces the same effect.
When encountering this issue, the procedure consists of a few steps: clear the browser’s cache and cookies, temporarily disable third-party cookie blocking in the settings, then restart the connection. You can also test in private browsing mode to isolate the problem.
If the homepage loads normally in private mode, it confirms that an extension or privacy setting is interfering. A detailed guide on the connection to CESI ENT with Apprendissimo outlines this procedure step by step with screenshots for each browser.
Microsoft 365 multi-factor authentication: the smartphone becomes mandatory
The CESI ENT relies on the Microsoft 365 ecosystem. The connection goes through the portal hosted on sts.viacesi.fr, with an identifier in the format of an organizational email address. So far, nothing complicated.
The game-changer is the activation of MFA (multi-factor authentication). When it’s in place on the account, every login, including from a desktop PC, requires validation on the Microsoft Authenticator app installed on the smartphone. In practice, even if you are working solely on a computer, you need your phone within reach.
Configure Microsoft Authenticator before the big day
The classic mistake is discovering the MFA requirement on the morning of a project submission. The app must be installed and linked to the CESI account before the first validation request.
- Download Microsoft Authenticator from Google Play (Android) or the App Store (iOS), then open the app and select “Add a work or school account”
- Scan the QR code displayed on the security setup page of the Microsoft 365 CESI account (accessible via aka.ms/mysecurityinfo)
- Test the validation by logging into the ENT for the first time from a browser: a push notification appears on the phone, just approve it
- Enable biometric unlocking of the Authenticator app to prevent a third party from validating a connection in case of phone theft
Without Authenticator configured, MFA completely blocks access and the CESI IT support is the only recourse to unlock the account.
Accessing CESI ENT on smartphone: Android vs iPhone
The situation varies significantly depending on the operating system. On Android, a CESI ENT app is available on Google Play, with an interface adapted for small screens and direct access to educational resources. You log in once, and the session remains active as long as you don’t manually log out.
On iPhone and iPad, the situation is different. There is no native CESI ENT app on the App Store. The recommended solution is to open the ENT portal in Safari or Chrome, then use the “Add to Home Screen” function. You then get an icon that behaves like an app, launching in full screen.
Home screen shortcut on iOS: the steps to follow
Open Safari, go to the CESI ENT portal, and log in. Tap the share icon (the square with an upward arrow), scroll through the options, and select “Add to Home Screen.” Name the shortcut, confirm. The icon appears on the main screen and directly loads the portal.
Feedback varies on this point: some users find that the session expires faster via this shortcut than on the Android app, requiring more frequent logins. Keeping Microsoft Authenticator active on the same iPhone makes the process quick, but this is something to anticipate.
Windows or Mac computer: browser and OneDrive synchronization
On desktop or laptop, access is via a web browser. Edge, Chrome, and Firefox all work, but Edge offers smoother integration with the Microsoft 365 ecosystem since it shares the same authentication engine.
OneDrive is natively integrated into CESI ENT on computer. Documents uploaded by instructors or shared in collaborative spaces are directly accessible, and local synchronization allows for offline work and then retrieving updated files upon going back online.
Avoid Microsoft account conflicts
A common pitfall on computer involves multiple Microsoft accounts. If you are already using a personal Outlook account or another professional 365 account, the browser may attempt to log in automatically with the wrong profile. The solution: create a dedicated browser profile for the CESI account. On both Chrome and Edge, profile management is done with a click on the avatar in the top right. Each profile retains its own cookies, sessions, and saved passwords.
- Create a specific browser profile with the CESI email address as the main identifier
- Do not enable synchronization with a personal Microsoft account on this profile
- Pin the CESI ENT tab for one-click access when launching the browser
This separation of profiles resolves most “wrong account” issues reported by students who switch between multiple Microsoft environments daily.
Accessing CESI ENT ultimately boils down to three systematic checks: cookies allowed in the browser, Microsoft Authenticator configured in advance, and a dedicated browser profile if juggling multiple Microsoft accounts. These settings take a few minutes and prevent nearly all blockages encountered throughout the year.
