SOLVED: Specific AD-user cannot login since a few days, please help debugging

Hello,

my problem:

One particular user is not able to login at the WUI any more. Looks like this problem started a few days back,
but in the last days we had so many issues (with Libre) that I did not watch into this particular.

Now, all users authenticate against our AD with LDAP.

Looks like most users are able to use AD-authentication and get to the WUI, but this particular user gets an ErrorException.
I posetd the the Lines in ~librenms/logs/librenms.log here:
https://p.libren.ms/view/0d0b8968

My version:

Component Version
LibreNMS 1.43-85-g8f89cd5
DB Schema 267
PHP 7.1.21
MySQL 5.5.60-MariaDB
RRDTool 1.4.8
SNMP NET-SNMP 5.7.2
====================================

[OK] Composer Version: 1.7.2
[OK] Dependencies up-to-date.
[OK] Database connection successful
[OK] Database schema correct

Btw. upgraded to PHP7.1 yesterday by running

yum swap php70w-common php71
yum install composer php-composer-xdebug-handler php-jsonlint php-justinrainbow-json-schema5 php-password-compat php-symfony-browser-kit php-symfony-config php-symfony-console php-symfony-dependency-injection php-symfony-dom-crawler php-symfony-event-dispatcher php-symfony-filesystem php-symfony-http-foundation php-symfony-http-kernel php-symfony-polyfill php-symfony-process php-symfony-var-dumper php-symfony-yaml php71w php71w-cli php71w-fpm php71w-gd php71w-intl php71w-ldap php71w-mbstring php71w-mcrypt php71w-mysqlnd php71w-pdo php71w-pear php71w-process php71w-snmp php71w-xml

I’ve seen in ~librenms/vendor/symfony/ that there was a polyfill-php70.
So I decided to move this folder away, then run

./scripts/composer_wrapper.php install --no-dev

causing to have rebuilt that folder polyfill-php70.
(Maybe not on issue… but should’n ther be a polyfill-php71 ?)

That username VALIDUSER is active in AD and credentials are valid (it’s actually the one that we use on our Libre system to authenticate at the proxy…)

Probably I just need to wipe some cache… but how?

Please help me to identify the root cause and how to fix this issue.

Best regards,
-awaum

ok… that was a layer-8-problem.

However, there seems to be something wrong with the error-handling of the WUI.

Reported BUG here.

polyfill-php70 is a library for providing some php 7.0 features on php 5.6, it is required by one of our dependencies.