ERR_SSL_PROTOCOL_ERROR on localhost

andrewn

ModEdit: Initial post restored.

Hello! I'm currently developing application on ASP..Net Core and have multiple browsers installed locally. Recently, for some reason, Vivaldi started returning ERR_SSL_PROTOCOL_ERROR when I try to open Non-SSL localhost endpoint. The same moment Chrome, Edge, IE and Blisk (Chromium based) open that page without any errors. I've already checked HSTS setting in Vivaldi and they contain no information for localhost
Any ideas how to fix this and what can be the problem?

lamarca

Welcome to the forums and enjoy Vivaldi Browser
Vivaldi Browser Help Center is available by hitting F1 key
Take your time to read the Community Code of Conduct

What Vivaldi version are you running?

andrewn

@andrewn Ok, sorry for disturbance, looks like this was some temporary problem, after a couple of reloads it started working
Just in case: Vivaldi version is the latest one from stable branch

lamarca

@andrewn Please, don't delete the initial post.
In case of a reply, there is no obstacle to deletion.

Flojan

I have still the same issue. If I want to open localhost:8080 i get the error message ERR_SSL_PROTOCOL_ERROR..

GearDoc47

@Gwen-Dragon said in ERR_SSL_PROTOCOL_ERROR on localhost:

@Flojan Your webserver on localhost does use a outdated SSL protocol or delivers SSL over a non-SSL port or vice-versa.
You should fix your webserver.

I also cannot access many locations.
Error:
"This site can’t provide a secure connection192.168.1.1 sent an invalid response.
Try running Windows Network Diagnostics.
ERR_SSL_PROTOCOL_ERROR"

I don't understand your answer.
Inet properties/advanced has TLS1.2 checked & no other ssl/tls set.
What is ones webserver? How does one fix?
Win7 desktop cptr, 32bit, 3.1.1906.3 (Official Build) (32-bit)
Trying to access 192.168.1.xx addresses
connection 192.168.1.1 is my router, 192.168.100.1 is my modem, 192.168.1.3 is my Ooma phone
Firefox, Vivaldi xp & Opera 12.18 on w7 & xp all have no problem accessing these addresses.
Thanks in advance for your help,
Greg

irvinborder

This post is deleted!