Link2SD: mounting /dev/block/vold/179:66 on /data/sdext2 failed: No such file or directory
You can use application "Apps2SD" mount a 2nd partition (after remove it and use Link2SD). (Don't use it if you only use 1 partition is sdext2) If you use android 6.0 and use both 2nd partition and "Adoptable storage" use "Root Explorer" go to path "/etc/apps2sd-mountscript.sh" edit it. Because use 2 partition, so default it use if create is "dev/block/mmcblk1p1 /data/sdext2", you change it to "dev/block/mmcblk1p2 /data/sdext2" (I use Sony M4 aqua dual)