Unwanted Black Line on my Render

[verysmallpingu]

When I render out my project, it shows a big black line on top of my render, but only when it finishes the render, its not there while its rendering neither at the viewport.

Anyone has an idea why this is happening?

An example:

Here is how it shows from the viewport on render mode:

[FedPete]

Check your objects!
Some of them can be hidden and instructed to be only visible when final render.

[verysmallpingu]

Thx , was one of the Grease Pencil Objects