Please help us help you and fill where relevant:
Your LimeSurvey version: Version 5.3.31+220815
Own server or LimeSurvey hosting: Root server
Survey theme/template:
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Starting yesterday p.m. without any known cause, an application using jsonRPC gets problems with get_session_key. A message appears, telling

Fatal error: Uncaught Exception: Unable to connect to www.xxxxx/q/admin/remotecontrol in /var/www/vhosts/xxxxx/httpdocs/b/f/JsonRPCClient.php:165 Stack trace: #0 /var/www/vhosts/xxxxx/httpdocs/b/f/includes.php(90): JsonRPCClient->__call() #1 /var/www/vhosts/xxxxx/httpdocs/b/f/survey-list.php(43): get_new_sessionKey() #2 {main} thrown in /var/www/vhosts/xxxxxx/httpdocs/b/f/JsonRPCClient.php on line 165

The PHP-commands calling json are:

$myJSONRPCClient = new jsonRpcClient( LS_BASEURL.'/admin/remotecontrol' );
$sessionKey= $myJSONRPCClient->get_session_key( LS_USER, LS_PASSWORD);    <

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this command throws the error

- The application runs for about 1,5 years without problems. It offers an UI to create new personalized versions of one sample survey.
- Calling LS_BASEURL.'/admin/remotecontrol' manually in Firefox gives the list of available functions, as it should do.
- Everyone that could have made a change in software or configuration swears to not have done anything.
- No automatic update of the OS (Centos) has happened (as far as I know).

If anyone has an idea about a possible cause, please tell me.

Many thanks in advance,
Erich

 

erichn wrote:

- Everyone that could have made a change in software or configuration swears to not have done anything.
- No automatic update of the OS (Centos) has happened (as far as I know)
 

Is the root server managed by IONOS? Or is that all done by yourself?
When I look at the root server I  see that you're using Plesk as a controlpanel.
The updates and configs can be changed by updates via Plesk too.
Not sure what version of CentOS you use but things like PHP will be not updated by CentOS.
I recommend to check changes in the Plesk ecosystem since the last time your application worked fine.

I would create a new directory with a simple connection php script to see if that works.
You might create a new site inside Plesk with different PHP settings etc

You're right! There was an update to Plesk just before the hourly check of our software. I tried to understand the mechanism behind the Json call to an non-existing file or directory (..admin/remotecontrol), but I'm not really familiar with PHP and gave it up.

So I did, what poor Windows-user must do sometimes, I restarted the server and immediately everything was working well. I hadn't restarted the server since start at one and a half years ago, so that simple solution didn't come to my mind.

Though some questions remain (mainly about functions inside Json), the machinery works again and I thank you very much for your help. Wish you a fine sunday!

With best regards,
Erich