I'm using Tasker on Android Lollipop (5.1.1). I've come to know that applications now can write to external SD card in Android 5.1.1 update but with the use of an API, for which the user needs to grant permission to the application. I have successfully done this with ES File explorer.
But, how do I give Tasker the permission to write to external SD Card?
(Click an image to enlarge it)
Have a look at https://groups.google.com/forum/#!topic/tasker/zuY21R_bvyU
where Pent said:
Here's a nice link explaining the situation:
https://groups.google.com/forum/#!topic/eyes-free/rspqjlmu_ss
As I understand it, if on lollipop or 'portable' mode on marshmallow are used, access is required via a special API. I've looked at this API (DocumentFile) and it's going to require rewriting huge chunks of code used for the file functions, plus some awkwardness with the user pre-accepting file operations
on external SD (and I don't know how long that preacceptance stays valid, potentially making it
useless for later automation)
Summary, I'm not going to be doing this in the near future, if more mainstream devices start to get SD I may reconsider.
Q & A