When trying to add a new reservation in the front-end management area, you might receive this warning.

The reason is that you should set proper permissions for the group that the user is being part of.

If your user is part of the "Registered" group, in the component back-end area, go to Options.

There you must set the values for Create, Delete, Edit to Allowed for the group Registered.

If the user is part of another group, you will need to change the values corresponding to that group.