As of 1.10, I no longer see Minecraft skins on any server. Only the standard skins can still be seen. I have reinstalled Minecraft many times and also reset the PC, nothing helped. Other games see my skin. I thank you in advance for the answers!
Set an output log to open (Launcher → Settings → "Open output log as soon as games start"), start Minecraft, look for the error in the output log, google it.
Hmm.
I would say it is your TP or your client (LabyMod / HackClient / BAC)
Thank you. I did not know the feature with the output log yet, thanks for your help!