Here is a VeryKool SL4502 LTE Stock ROM Firmware which can be used to load and flash stock firmware on any VeryKool SL4502 LTE of this exact variant. Any MTK Flash tools can download and flash this VeryKool SL4502 LTE flash file on your SL4502 LTE so long as that MTK Flash Tool supports MTK Scatter File.
Since most major software malfunctions on any MTK Android devices can only be corrected by flashing, this SL4502 LTE flash file, if properly used, can unbrick (debrick) your SL4502 LTE and also corrects any software issues your VeryKool SL4502 LTE may currently have. Also, keep in mind that when you load stock firmware on your VeryKool SL4502 LTE using any MTK flash tool, your VeryKool SL4502 LTE will be reset to factory defaults settings and by that, definately, your UserData will be lost including contacts, messages and others.
Note: If your SL4502 LTE is already bricked and you want to unbrick it, you will need to pay closer attention to the tutorials contained below here.
VeryKool SL4502 LTE Stock ROM Firmware Download Link(s)
1. VeryKool SL4502 LTE (Android 5.1)
How to Flash Stock Firmware On VeryKool SL4502 LTE
1. Download your VeryKool SL4502 LTE stock ROM firmware from the link above.
2. Extract the VeryKool SL4502 LTE Firmware you downloaded from the link above onto a folder on your PC.
3. Download and install MTK android device drivers on your PC. You may skip this step if you have installed MTK drivers on your PC already otherwise, download MTK drivers here
4. Now, choose either of the tools listed below here to load the stock firmware on your VeryKool SL4502 LTE.
2. NCK Box
3. Miracle Box
See video tutorial here: How to Flash MTK Android Devices Video Tutorial
Note
1. Each of the tools listed above contained step by step guides with illustrated pictures on how to flash stock firmware on your VeryKool SL4502 LTE.
2. If your device is bricked already, I recommend that you use NCK Box or SP Flash. Both are the safest toolS for flashing MTK Android devices.
3. If you require any further assistance, simply drop your comment detailing the issue(s) and I shall help you revive your VeryKool SL4502 LTE, if need be.