small white dots with black circles around at reflective mats

hi does someone know, what these spots on the complete reflective chainlink are?
tried some rendering adjustments and stuff, but couldnt fix it.
i changed GI solutions and turned off/on ambient occ. changed some subdivs to higher values..
perhaps someone of you know when these spots occour.

the scene is here

thank you in advance!

small white spots fixed

found it and fixed it:

it was the sun size. (vray sund and physical cam used in this scene)
decreasing the sun size multiplier decreases the spots. turning the sun “invisible” removes them completely.

perhaps some weird reflection issue?

the issue is using a sharpening filter with images that contain pixels brighter than 1.0. as you found out you can either check the sun invisible, and lose those bright reflections, or clamping the output and turning subpixel mapping on.
or simply avoid sharpening filters.

wow thank you rivoli for clarification!