If you install an iLok license and it is displayed as Queued on the iLok Manager it can be for the following reasons.
A first generation iLok only allowed for one product's license to reside on it at one time. Any other identical licenses would then be queued. This does not occur with second generation iLoks because second generation iLoks allow for multiple licenses of the same product to reside on it.
There are two issues here based on the screenshot. The first is currently the expired NFR license for Revoice Pro 3 is on the iLok so that license cannot be use to authorize. The second issue is that the expired license is an NFR and the new license the user is trying to use is a trial/demo. A trial/demo license cannot activate a NFR or regular license. Only a untimed license, time-limited license or another time-limited NFR will allow authorization again once all other activations of Revoice Pro 3 have been deactivated from it.