'Unparseable license format' error when applying pool license

My first suggestion would be to upgrade to version 4.6. There has been a lot of testing/hardening between 4.4 and 4.6. It appears you may have hit Bug 570732.

Here is the workaround suggested in that bug: Here is what the customer needs to do:

1. Navigate to their license's properties

    

2. Click "Reactivate" Note: since this license has already been put into "manual activation" mode, they must do manual activation again.

    

3. Click "Generate dossier" They can ignore the dossier if they already have the license text, they just need to re-input it. If, on the other hand, they have misplaced their license text, it may be simplest just to go through the full activation process again with the web portal.

    

4. Input the license text. Make 110% sure there are no leading or trailing blank lines, or any other stray input.

    

5. Complete the activation.

    

Now, they should be able to license their BIG-IP.