What i observed for manual sort is sometimes i need to click on the save sort and at other times it remembers sorting without clicking save sort,make it auto save on redragging
It should be automatic if Preferences / Folders / Columns and Sorting / Automatically save manual sort order where possible is turned on, and the criteria mentioned in the manual are all met:
https://www.gpsoft.com.au/help/opus12/index.html#!Documents/Manual_Sorting1.htm
That's already turned on,still i need to click save sort sometimes.
As far as we can tell, it works.
If you can work out a pattern or trigger regarding what is being done in cases where it doesn't work, let us know and we can investigate it. For example, maybe it doesn't save if you change folders or close the window in certain ways we haven't thought to test, and works when doing the same thing in other ways.
After i reposition files i go one or two folders up in bcrumb and changed folders,and it didn't work
I've tried the same and it saves the sort-order correctly. So it cannot be just that.
When you return to the folder, is manual sorting actually turned on, or is it off again?
There are two separate things: Whether manual sorting is on or off, and what the sort order is if it is on.
Whether manual sorting is on or off is controlled by Folder Formats, and never auto-saved for a folder. Only the sort order gets auto-saved. If you want manual sorting to always be turned on for a folder, you need to set up a folder format for it to do so (unless it's turned on for all folders via one of the formats that are used by default).
Sorry,I forgot to say that it was in previous versions it didn't work properly,I tested again most of the times only it is saving on changing folders and going up and down in bcrumb and rarely it doesn't.
I'm using manual sort toggle and it's enabled on return to folder
reason might be bcoz I'm using custom folder icons
That would set the read-only flag on the folder, which may have caused problems several versions ago. As far as I can tell from testing, it shouldn't cause problems in 12.16.
The only thing I've found so far is that if you exit the program, rather than change folders or close the window, then changes to the sort order don't get saved.
To repro u have to test in 4 to 5 folders and the test i did was in latest ver,it's not saving
Pls note - whenever if u can't repro a bug normally do thorough testing
Please don't insult us. 
We know how to test things. The problem is that there isn't much information to go on here.
Please also, as per my warning a few days ago, desist in sending me posts, direct messages and emails with unsolicited "health tips", or about your religion, or containing photos of nude women. I've said already that I am not interested in these communications from you, and they in no way make up for your history of abusive messages (on the contrary, the add to it). Stick to the topic of Directory Opus. No more warnings about this stuff.
How do I turn off "control manual sorting" globally,. As described here, about halfway through the page https://www.gpsoft.com.au/help/opus12/index.html#!Documents/Manual_Sorting1.htm
I have tried unsuccessfully, thank you
If manual sorting is turning on automatically when you enter a folder, then you must have done this (from the page you linked):
You can also turn on the Sorting Options / Manual sorting option on the Display tab in the Folder Options dialog. Obviously as a folder options setting, this mode can also be made permanent by saving the folder format.
You can turn it off again in the same place and re-save the folder format to undo that.
You can see all your saved folder formats via Preferences / Folders / Folder Formats, if you want to check which have manual sorting turned on and turn it back off in them.
Or you can follow Folder Formats: Quick Guide to apply the same format to all folders and remove any custom formats for specific folders.