If the number of licenses for some SKUs selected during License pool configuration are negative or doesn’t respect certain conditions, then CoreView tenant admin won’t be able to save changes using Manage License Pools function.

You can edit the existing license pools from License pool report to avoid having negative number of licenses. So, the assigned must be more or equal to consumed number of licenses per each license pool, while total assigned must be less or equal to active units. Please see more details on how to modify license pool report here.

Then, check the conditions to be respected under license pool tab while editing existing License pool using Manage License Pools function: assigned must be less or equal to total available number of licenses for the selected SKUs. 

This condition can be respected if you do not have any negative numbers under license pool report (no red arrows). So, if you make the necessary modifications in the license pool report, you should be able to edit existing license pool using Manage License Pools function and save the changes.