should i do the remote desktop client update 3.9.2

No please do not update. I am having keyboard and trackpad freezing.

I have to press shift+control+option and power down.

After restart it is working.

But after awaking from sleep it is nightmare. You need to shutdown completely and after some time if restart it will work

Do NOT update!
A series of bugs integrated into the new update. Remote Desktop worked fine before the update and now there are several serious bugs: Shortcuts on remote computers do not work anymore (Shift or alt key) and some(?) clients have a 10 second delay before you can get screen access.

Apple is the most overrated company in the world...

As you can see from the threads on this discussion board, the ARD 3.9 upgrade is likely to kill the app, which is a serious problem for many of us. I'm a professor who uses it many ways every day for a studio with 26 iMacs. This has been sent me scrambling for work arounds for a few weeks. I check at least once a day for updates to the client and admin software.

I wish Apple would at least acknowledge the problem, if not suggest a solution. Reverting a couple dozen machines without ARD in the middle of the semester is not an option.

So I can't recommend the update. You're lucky to have the old, working version.

Sorry its a bit late but if you haven't upgraded yet then don't and definitely don't upgrade your ARD Admin to 3.9 it has issues, big issues!