The reason why we can't find the solution for this issue is that the answer is very simple. You just change user usergroup to Moderator. Nothing else is needed.

Also you should know that Moderator has no access to Dashboard Forum Menus. Moderators moderate topics using front-end buttons explained here:

https://wpforo.com/docs/root/admins-and-moderators/topic-post-moderation/

Do you have other questions and issues related to this?

first, I would like to say Thank you very much! I've asked you many questions in the last 3 months. You have helped me a lot! I Have install wpFoto and bought 2 addons from you for my 2 websites. I'm already a fans of your company. I've used to use your wpFoto and recommend it to many of my friends.

However, I'm disappointed in this case. I must clarify --------- My question is "How to set a member as a Moderator" (please see the title of this topic). It should be a small issue, but I don't know why it's so difficult to fix.

Ok, I won't ask more questions. But I hope you can give this case "How to set a member as a Moderator" to another staff.

I don't want to complain your customer service,  you have answered many questions for me. Generally, your customer service is quite good! Thank you!

I guess quite a few of your customers are beginners. You could make some tutorial videos (such as "How to set a member as a Moderator") for the frequently asked questions. When these FAQ is asked, you can simply give the customer a link to show him how to do step by step by himself. In this way, your customer service can save a lot of time and your company can save cost.

Please give me a link when the tutorial video of  "How to set a member as a Moderator" has made. Thank you in advance!

The Edit button is correct. You should click on that button and set the user Usergroup Moderator.

Also, you should know that Moderator is not admin and he/she should only see the Moderation menu. That's correct. Moderator should not see other  admin menus. moderator should moderate on forum front end using these tools:

https://wpforo.com/docs/root/admins-and-moderators/topic-post-moderation/

Thank you for your time!

Are you sure you don't set yourself Moderator? ------ No

Please edit your user and make sure you're admin. ----- Yes.

Make sure you use Edit user button not the Your Profile menu of the Users menu area. ------ Please have a look at this screenshot - have I gone to the correct place?

Thanks.

So, you say, you're WordPress and wpForo admin and you can't see forum dashboard menus? is this the problem?

Ps, Following your instruction, I've disabled "Role-Usergroup Synchronization", are you sure this is correct?

Yes that's correct.

Please edit your user and make sure you're admin. ----- Yes.

Make sure you use Edit user button not the Your Profile menu of the Users menu area. ------ Please have a look at this screenshot - have I gone to the correct place?

Thanks.

Sorry, I've tried, but it doesn't work. After I've disabled "Role-Usergroup Synchronization", yes,  the Usergroup drop-down menu is active and I'm able to select the moderator Usergroup. But after I set a certain member into a moderator, it doesn't allow me (admin) to go ahead (screenshot6,7,8), and also under the Forum Menu (left), almost all the sub-menu disappear (screenshot9). Please have look. 

Very sorry for giving you trouble again.

Are you sure you don't set yourself Moderator? Please edit your user and make sure you're admin. It seems you've set Moderator yourself not other users. Make sure you use Edit user button not the Your Profile menu of the Users menu area.

Very sorry for giving you trouble again.