I have tried many ways of connecting. It seems to link, contoller and mini2 seems to follow the guide. I downloaded the latest Fly app and no difference in linking. The phone is a Samsung Galaxy 8+. I've tried it whith a DJI Spark and it works. The mini2 not connecting to the controller is what the app says.  I have a mini ipad4 that I but can try but the Samsung should work.

Hi. As mentioned in a couple of other posts, the controller will not connect if you have long file names in the memory card. I believe you can try connecting without a memory card inserted. Otherwise take a look at the memory card in a PC and see if any file names are longer than those written by the drone. I had renamed mine for clarity and then could not pair.

I will look  into this.

DroneyK does "file name" mean the names of videos and photos in the photo folder?   (DCIM/100 perhaps? )  
I have seen "unable to connect"s that were fixed by removing the card, saving the photos and reformatting the card etc. but this is, I think, the first mention I have seen of it being due to long file names. I might have seen mention of it disliking non std photo/video names but can't be certain. NOT arguing just seeking education.