Open URL not working

[johnnyboy1984]

Hello,
I noticed that since a few months i don't get an SMS from clickatell anymore that is triggered when my alarm goes off.
After some searching and trying i found out in the Error log my URL's aren't sent anymore:
Error: Error opening url: platform.clickatell.com/message.....
I tried the same URL in the browser and there it works.
Also another URL in Domoticz to tilt my camera's (PTZ) is not working in domoticz anymore, so it is not an incident on one url adress.
Anybody got a clue where to look?
Thanks!

[waltervl]

Is opening the url with curl from the Domoticz server working?
If on docker do it from the Docker container.

[johnnyboy1984]

I am not running domoticz from Docker. How can I open an URL from the server?

[waltervl]

start a terminal session on your system (I do not know how that works on a Synology nas) and give the command:
curl <URL>
change <URL> with the URL you would like to test.