All my MT4 Platforms showing the same Error since last Weekend

maybe somebody has an Idea, what could cause the above mentioned Error
- showing following in the lowest right field in the MT4
first "general error", shortly after showing "account not valid"

I even reistalled 2 of my MT4´s, still showing the same error

I ran out of ideas...

Your demo has expired ...

thank your for your answer

I of this 2 MT4 is not a demo - its a live account, where I am in a current trade

I contacted my broker, he told me to resinstall the platform

I did as told - I even changed the password...

I still getting a messege "general error"

I ran out of ideas

If it's a Live account, that's a serious issue you have here and your broker should be urgently contacted to find a solution.

if you re-install, make sure you delete ALL folders/files (not sure if the deinstallation-routine deletes all), and make backups of your scripts, indicators, eas, etc. ...

C:\Users\YOURUSERNAME\AppData\Roaming\MetaQuotes\

thanks for your help till now

even a fresh downloaded demo from any other broker does not work

I do not really understand, why this all is happening

even if I try google search for "connection failed on MT4", I get very few results

what else could cause this error?

my firewall? ( it never was a problem ...)

any other configuration of my PC or my WLAN network could cause this?

( maybe to mention, that any loggin datas in real or demo version on my MT4 isw not getting safed )

I ran out of ideas....

I found out, that the place, where I am now, has a kind of "surf protection" installed -
FortiGuard from Fortinet..

as well, my Teamviewer can not find any Internetconnection, even if I am online, writing this here

has anybody an idea, how I could go around this Fortiguard by using my MT4?