Thank you mate for a detailed tutorial! Much appreciated!

ERROR 86006
SOLUTION

HOW TO RESOLVE AND CORRECT THE ERROR 86006 !!!
Why many attempts I finally received the error and come here to share with you!

Note: It’s no use trying as new rooms is not working, I have just like older rooms. In the case here was the XIAOMI Redmi 5 Plus, but you have seen in several forums an old ROOM solution solution.

Tutorial:
01) Download and install XiaoMiTool: http://www.xiaomitool.com/
02) Download a GLOBAL FOURTH older than your device at: http://miui.com/download.html?from=miuiindex
In the case of Redmi 5 Plus, a SALA would be this:
Version: 8.3.29 (MIUI9)
miui.gif
Link Download direct: http://bigota.d.miui.com/8.3.29/miui_HM5PlusGlobal_8.3.29_c79631bb41_7.1.zip
03) Paste a ROOM that you downloaded in: C: \ Xiaomi \ XiaoMiTool \ rom
04)
05. Note: This process will be created and run on your computer, so you will back up your dataset if you wish.
a) Open XiaoMiTool and follow the steps shown on the screen to update a FOURTH.
Use the list of the ROOM version that you put in the C: \ Xiaomi \ XiaoMiTool \ rom folder and disregard the other ROOMS in the list (try as other ROUTES in the list only when using the incorrect 86006 error after installation)
06) After XiaoMiTool finishes the update of the ROOM, make your device complete until you close the screen
07) Now turn on your cell phone and activate your XIAOMI account (ID + PASSWORD that connects your XIAOMI phone), after connecting the device,
Go to: CONFIGURE / ON YOUR PHONE / click 9x very fast on: MIUI VERSION / click BACK / on SYSTEM & DEVICE go to ADDITIONAL SETTINGS / DEVELOPER OPTIONS /
Check only:
1 developer options
2 USB debugging
3 Verify applications via USB
4 closed applications to force
5 Enable MIUI optimization
If prompted to restart the default
08) Go to: CONFIGURE / ON THE PHONE / click 9x very fast in: MIUI VERSION / click BACK / in SYSTEM AND DEVICE go to ADDITIONAL SETTINGS / DEVELOPER OPTIONS / click MY STATUS UNLOCK / ADD ACCOUNT AND DEVICE
09) If you are not wrong 86006 follow the following steps, if the error persists, repeat the steps from 01) to 08) above with a different room (the older the room the better)

10) For those who do not have more error 86006 follow below:

11) Download version 2.3.803.10 or more.
Link Direct Download: https://xiaomifirmware.com/downloads/download-mi-unlock-2-3-803-10/
12) Open the miflash_unlock.exe file and follow the on-screen instructions to unlock
If you did not automatically install the USB driver
Click “MiUsbDriver.exe” to install the USB driver.

13) If all goes well for a period of many hours, the hours arrive and repeat step “12)”.