I too have the APPLY button problem. I will try to add a screenshot describing the problem but anyway. For example when I try to exclude jetways, I select all with jetways, then click on exclude. When I press APLLY nothing happens.
Yes, I can see the error in your log and I can replicate it too, so it will surely fixed soon.
I couldn't replicate the one shown in the video from airbadger, where he was editing the Settings page, your issue is the scenery editor page.
I also would like to know if there is a possibility for me to go back the software before update?
Only if you have a previous installer, and install it by disconnecting the network. This question always come up when we have a new update, then in a couple of days, when we fixed all the updates, nobody wants the old version anymore. The version you want to go back to, is the one some people wanted to rollback, when it came out...
A slightly off topic issue is the "universal installer". When I try to click on UPDATE button the program does the update but then it still shows "UPDATE 1 SELECTED".
That's how it's supposed to be.
That button is only telling you how many products WILL be updated WHEN you Press the Update button, and the number it's the number of products selected in the grid, because you can do a multiple selection by CTRL+Clicking the various products, so the number it's useful to let you know that, in case you press the update button, how many products will be updated.
That's why there's an "Update ALL" button as well, which will update all products regardless how many you have selected.