After taking down the artillery , you have to destroy 3 bases on this mission , but you can't build military buildings , so your only option is to build a Landing Zone to bring your units from the Main Base to the Mission Area , at first , It worked fine , I transported the units from the Main Base to the Mission , but after half an hour of playing , when I was attacking the Southeastern base , I built a Landing Zone nearby but I couldn't transport any units from it , there is no ''Call Transporter'' button on it and , if I try to send the transporter from the Main Base , i hear the ''Transporter has arrived'' voice but no transporter on the Landing Zone ! I also already sold the first Landing Zone I used to transport the units the first time.

Any solutions or reasons why this happens ? I don't feel like restarting .