Can't upload thumbnail in steam workshop

[MrSnooker1998]

I can't upload a thumbnail in steam workshop, I doing all from stellaris wiki ant this doesn't work. This is first mode what i wanna share in steam. Mod upload in steam but still without thumbnail.
Wersion Butler v2.8.1(dfce) in launcher
In Game Butler v2.8.1 (7d86)
I have all DLC except Necroid Pack

A code in "Mass Effect pack by MrSnooker.mod looks like:
version="0.3.0"
tags={
"Species"
}
name="Mass Effect pack by MrSnooker"
picture="thumbnail.png"
supported_version="2.8.1"
path="C:/Users/MrSnooker/Documents/Paradox Interactive/Stellaris/mod/Mass Effect pack by MrSnooker"
remote_file_id="2296545861"

This is a file, this have 512px x 512px weight 366kb


I don't know what's wrong. Please help.

 

[MrSnooker1998]

I managed to do it. you can close the thread

 

[Pyzayt]

...So, what did you do to get it working? It might be beneficial for others also having this issue to know what your solution was.