To unblock a user from the VIGIE portal, go through the following steps: 

Step 1: In the main menu, on the left side, click on Users Management. 

Step 2: Select the user you wish to unlock. A side window will open with the user's data.

Step 3: At the bottom of the side window, under actions, click Unlock user. 

Step 4: You will get a warning saying "Are you sure you want to block this user?". Click on the Yes option. 

Example of how to unlock a user: