After updating to LR 2015.8 there are selection bugs in organize and develop mode. i cannot select a group and put them in a collection or so. Also the smugmug export doesn't work anymore. I also make a bug report to the smugmug team about this.
"i cannot select a group and put them in a collection or so."
It's best to put each issue in a separate topic. I suggest you post this in a new topic by itself and include a lot more detail about what isn't working. A full-resolution screenshot of the entire LR window can be very helpful.