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To be able to use the Availability Check with Contents we recommend you to use the field Requested Contents in the Media Configuration. You can enter the number of the Contents you requested there.
You can also get this field filled automatically by the system with the number of Contents you have selected. Ask your administrator to enable the feature “Calculate number of Requested Contents“ for you on the Administration Settings page.
For more information about the Availability Check please take a look at the Wiki page Check Availability for Exclusive Products.
If you can not see the field in your Media Configuration layout please ask your Administrator to add it following the steps described in this article: 7.2.2.10 How to configure the Content selection in Media Configuration.
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7.2.2.10 How to configure the Content selection in Media Configuration
7.2.1.1 Administration Settings to enable the feature “Calculate number of Requested Contents“