If I paid for Rekordbox could I get help making it work with my 900s?

Yes you can. Rekordbox DJ Works with CDJ2000, CDJ2000Nexus, CDJ900, CDJ900Nexus, CDJ850, CJ350 and the XDJ1000.

It's all here https://rekordbox.com/download/func/func_multiplayer_equiv_en.html

CDJ-900 is supported and you can try the connection in 30-days free TRIAL by following steps

1. Start TRIAL
2. Select [PERFORMANCE] mode by clicking dropdown menu on the upper left of the rekordbox 4 GUI
3. Connect CDJs to your laptop via USB cable (not Eathernet cable.)
4. Push [LINK] button on CDJs
5. Push browse rotary encoder of CDJ to connect
6. Turn the browse rotary encoder to select the deck number (typically, set to 1 and 2).
7. Now you can control rekordbox by using CDJs

Maybe I am wrong but he may be asking for help with Rekordbox itself. I am only guessing this because he said "I need serious help and have gotten nowhere for months." and Rekordbox DJ has only been out for a few days so there is no way he could be having trouble or success with Rekordbox DJ for months.

But to answer this bluntly YES CDJ-900 Works with Rekordbox and YES it works with Rekordbox DJ. It is very easy to get working so I would suggest reading the manual. TBH this is something you may want to grasp on your own as it is certainly not going to get any easier if you simply have someone else do it for you.

In other words if you start DJing professionally and something goes wrong someday you will have nobody but yourself there to help so may as well get as much education on this while you can and there are is no pressure. Believe me the experience WILL come in handy more times than you want to believe :)

Hey, thanks for this but I promise it's been windows 10 + CDJ-900. it's fine on my windows 7 laptop and all works fine. "for months' since I've had my other laptop (newer with windows 10) I've not been able to use it with my CDJ-900's. I've read the manual, I've read the support thread and tried everything. I swear I'm not dense or anything. This is some obscure thing I don't know how to fix.

To clarify though you are attempting to get Rekordbox itself to work and not Rekordbox DJ correct? If so you should NOT have to purchase RBDJ in order to get RB (via LAN cable etc) to work with your current hardware/software.

Right , I haven't purchased DJ yet. I want it to work with my CDJs as is with my new laptop before I drop 129.00. This has been an unsolved issue.

You can download and use rekordbox 4 in EXPORT mode without having to pay for it. Only once you open PERFORMANCE mode do you engage the 30 day trial (you have to click a button to start it).

EXPORT mode allows you to continue using rekordbox 4 as you currently do with rekordbox 3; you can export to devices, link to CDJs, etc.

PERFORMANCE mode is what turns the software into a DVS-type software, with the players acting within the software and the CDJs as controllers.

If I am not mistaken the issue here is he is not able to use his CDJ-900's with previous versions of RB.

@ Casnik77 - Pulse brings up a good point. It is unlikely but have you tried simply downloading and installing the new version (4.0) of Rekordbox and seeing if that alone rectifies things? I mean it couldn't hurt as your old version of Rekordbox remains after installation of RB 4.

If still nothing I would attempt the steps posted above (by Shimpei Aso) above as this is free as well as Pulse mentioned. Again...................... it couldn't hurt and I always say anything proactive is better than waiting for things to fix themselves :)

No you're missing this entirely. The network link doesn't work with a new laptop (Laptop A). It works on Laptop B as far back as version 1.0 and works now with version 3.3. I haven't updated yet on that laptop B. Laptop A has had V3.1, v3.2, v3.3, and now v4.0 and it hasn't worked with the CDJ's at all, just shows Link but no CDJs.

Laptop A (new laptop) Link button shows , but no CDJ's appear.

Laptop B Windows 7 laptop it all works fine.

I want to purchase DJ version of Rekordbox but not for old laptop B. I want Laptop A to work because it's got way better components.

Make sense?

Rekordbox DJ uses USB not network link (ethernet) as previous versions of RB did so you have nothing to lose as the trial is free and you have so much to gain. Keep in mind THIS would be the time to find out anyways. You can DL & install and IF it does not work you can troubleshoot accordingly with the wonderful Pioneer staff here.

Can I use it on 2 laptops?

I can control the CDJs but I am getting no sound.

Have you set the output to the proper device in the settings? As far as using it on two laptops I would say..................... download and try. I purchased day one so I am not 100% sure about the free trial.

Where is the manual for this? I'm solving my own issues sort of... but this is just full of automatically changing of settings after you change it.

Frustrating but if I can get the manual maybe I can read up.

i've got the sound set up like Pioneer CDJ ASIO with output 1 as CDJ-900 1 L and R and then output 2 as CDJ-900 2 L and R

All sound plays through deck #2

????

https://rekordbox.com/en/support/manual.php

Nothing in the manual shows me why 1 deck plays both channels. ugh... this is really frustrating.

Now I'm noticing the analysis of my tracks has taken a skew on the quantizing. It's off in a lot of tracks.

Tracks are taking in excess of 30 seconds to load from an external drive. Haven't tried moving my collection to an internal yet... but 30 seconds is ... wow

Yes, you can use the license on two computers.

You've likely misconfigured the ASIO output which is why you're having troubles there. If you're using the CDJs with Windows 10, that could be the source of the problem as there is no official support for Windows 10 for any Pioneer product other than rekordbox 4.

The quantization can be adjusted to various levels, this could explain why you feel it's "off."

My music collection is all located on external and I've not experienced any lag in loading tracks. What format is the source drive and is it USB or network? What are the file types?