Hey Luis!
Welcome to planDisney and thanks for dropping by!
When purchasing a Disneyland Resort
Theme Park Ticket directly from the official website or
Disneyland Mobile App, you select the dates you plan to visit the resort. This process creates a
Theme Park Reservation during the ticket purchase transaction. The reason the system states “Unable to Make a Theme Park Reservation” is that you already hold the necessary reservation.
To confirm your reservation, you may log in to your Disneyland Account and select “My Disneyland.” Then, click “Ticket and Reservation Details” from the dropdown menu. Lastly, click on the “My Park Reservations” hyperlink. You’ll see the theme parks you selected from June 25th through 28th. This information can also be found in the "Future Plans" section of the Disneyland Mobile App.
Please head back to planDisney with more Disneyland Resort questions!
Tiffanie