It does seem like there is some sort of confliction between dlc 1 and 2. 2 seem to like to restart the game fully while 1 let you resume playing I'm on Android as well
Maybe not I had to fully restart the game and redownload dlc 2 before it would install
Sorry, the message might not appear in some cases but the button should become availble instantly if DLC was loaded.
Your good it work in the end keep up the good work