Sorry..it did not work. I did download the CGminer again from the link you provided. Thanks in advance.
This is the text in the .bat for one of my pool workers (R9 270x):
cgminer --scrypt-jane -g 2 --worksize 256 -I 9 --thread-concurrency 16384 -o stratum+tcp://utc14.yacoin.club:3413 -u [change to your worker name] -p [change to your password] --sj-nfmin 14 --sj-nfmax 14 --no-submit-stale
* Note: This .bat text specifies "--scrypt-jane" and does not use --sj-time 1446256800. This works. Try it.
I tried these settings on two of my R9 270 rigs, and both froze within few seconds. I tried -I 5 on seconda rig, but it still froze.
Edit: mining started when I changed to -g 1, but I only get around 550 H/s with R9 270. That seems quite low compared to 1.1 KHs with GT 720 you mentioned.
Performance across brands can vary. R9 270 is not the same as R9 270X. 2gb vs. 4gb can have an impact. Many variables. I have some HD 7950s that under-perform on higher settings. Yes, not entirely the same case, but it gives me some ideas.
First, try a very basic .bat to check what your baseline is:
cgminer --scrypt-jane -o stratum+tcp://utc14.yacoin.club:3413 -u [change to your worker name] -p [change to your password] --sj-nfmin 14 --sj-nfmax 14 --no-submit-stale
Then try this (just add -I setting) to see if things improve:
cgminer --scrypt-jane -I 9 -o stratum+tcp://utc14.yacoin.club:3413 -u [change to your worker name] -p [change to your password] --sj-nfmin 14 --sj-nfmax 14 --no-submit-stale
Finally, try this (settings about 50% of the original .bat info posted):
cgminer --scrypt-jane -g 1 --worksize 128 -I 9 --thread-concurrency 8192 -o stratum+tcp://utc14.yacoin.club:3413 -u [change to your worker name] -p [change to your password] --sj-nfmin 14 --sj-nfmax 14 --no-submit-stale
A couple of things to really pay attention to: Intensity (-I) and --thread-concurrency are great for augmenting hash performance - to a point. Too high will greatly slow down, or lock up your whole rig. -I too high will also generate hardware (HW:) errors. Lots of HW is wasted hash - you are just heating the room, not solving blocks.
Every rig is different. Experiment, and use whatever gives you the optimal result.