Horizontal Black Lines in Output Render

[Jonazaru]

Suddenly getting horizontal black lines in my output renders, never used to happen before, any ideas as to why this might be occurring?

[Catherine]

Please go to Edit > Preferences > Performance tab and set the Use OpenCL hardware acceleration to No OpenCL acceleration. Please try rendering the stack again and let us know if this helps.

If not, please go to main menu > Help > Deactivate, to deactivate current license registration, then register the license again: Help->Register online..., and enter the ******** activation code.