After upgrade to bbb v2.0.0

Hello all,
after updating the bbb-integration to version 2.0.0, I get the following error message:

{"reqId":"burRGhbLd6TPNpsn5i2l","level":3,"time":"2021-08-01T16:27:25+02:00","remoteAddr":"...","user":"...","app":"index","method":"GET","url":"/index.php/apps/bbb/b/DY4b8pcEqWfjdNdq","message":{"Exception":"Exception","Message":"Can not create meeting","Code":0,"Trace":[{"file":"/home/.../public_html/nextcloud/apps/bbb/lib/Controller/JoinController.php","line":129,"function":"createMeeting","class":"OCA\\BigBlueButton\\BigBlueButton\\API","type":"->"},{"file":"/home/.../public_html/nextcloud/lib/private/AppFramework/Http/Dispatcher.php","line":218,"function":"index","class":"OCA\\BigBlueButton\\Controller\\JoinController","type":"->"},{"file":"/home/.../public_html/nextcloud/lib/private/AppFramework/Http/Dispatcher.php","line":127,"function":"executeController","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->"},{"file":"/home/.../public_html/nextcloud/lib/private/AppFramework/App.php","line":157,"function":"dispatch","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->"},{"file":"/home/.../public_html/nextcloud/lib/private/Route/Router.php","line":302,"function":"main","class":"OC\\AppFramework\\App","type":"::"},{"file":"/home/.../public_html/nextcloud/lib/base.php","line":993,"function":"match","class":"OC\\Route\\Router","type":"->"},{"file":"/home/.../public_html/nextcloud/index.php","line":37,"function":"handleRequest","class":"OC","type":"::"}],"File":"/home/.../public_html/nextcloud/apps/bbb/lib/BigBlueButton/API.php","Line":134,"CustomMessage":"--"},"userAgent":"Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:90.0) Gecko/20100101 Firefox/90.0","version":"21.0.3.1","id":"6106b015bdaf7"}

Unfortunately, I can no longer revert to version 1.4.2.
I would be very grateful for your help.
Christian

**Operating system:** Linux 5.12.18-051218-generic #202107190932 SMP Mon Jul 19 09:36:27 UTC 2021 x86_64

**Webserver:** Apache (cgi-fcgi)

**Database:** mysql 8.0.25

**PHP version:** 8.0.8

Modules loaded: Core, date, libxml, openssl, pcre, zlib, filter, hash, json, pcntl, Reflection, SPL, session, standard, sodium, cgi-fcgi, mysqlnd, PDO, xml, apcu, bcmath, bz2, calendar, ctype, curl, dom, mbstring, FFI, fileinfo, ftp, gd, gettext, gmp, iconv, igbinary, imagick, intl, ldap, exif, msgpack, mysqli, pdo_mysql, Phar, posix, readline, redis, shmop, SimpleXML, smbclient, sockets, ssh2, sysvmsg, sysvsem, sysvshm, tokenizer, xmlreader, xmlwriter, xsl, zip, memcached, libsmbclient, Zend OPcache

**Nextcloud version:** 21.0.3 - 21.0.3.1

**Updated from an older Nextcloud/ownCloud or fresh install:** 

**Where did you install Nextcloud from:** unknown

<details><summary>Signing status</summary>

Integrity checker has been disabled. Integrity cannot be verified.
</details>

<details><summary>List of activated apps</summary>

Enabled:

  • accessibility: 1.7.0
  • activity: 2.14.3
  • admin_audit: 1.11.0
  • announcementcenter: 5.0.0
  • appointments: 1.9.3
  • apporder: 0.13.0
  • bbb: 2.0.0
  • bruteforcesettings: 2.2.0
  • calendar: 2.3.0
  • circles: 0.21.3
  • cloud_federation_api: 1.4.0
  • comments: 1.11.0
  • contacts: 4.0.1
  • contactsinteraction: 1.2.0
  • cospend: 1.3.7
  • dashboard: 7.1.0
  • data_request: 1.8.0
  • dav: 1.17.1
  • deck: 1.4.3
  • drawio: 1.0.1
  • event_update_notification: 1.3.0
  • extract: 1.3.2
  • federatedfilesharing: 1.11.0
  • federation: 1.11.0
  • files: 1.16.0
  • files_antivirus: 3.2.1
  • files_downloadactivity: 1.10.0
  • files_linkeditor: 1.1.5
  • files_mindmap: 0.0.24
  • files_pdfviewer: 2.1.0
  • files_rightclick: 1.0.0
  • files_sharing: 1.13.1
  • files_trackdownloads: 1.10.0
  • files_trashbin: 1.11.0
  • files_versions: 1.14.0
  • files_videoplayer: 1.10.0
  • firstrunwizard: 2.10.0
  • forms: 2.2.4
  • groupfolders: 9.0.2
  • impersonate: 1.8.0
  • integration_discourse: 1.0.0
  • integration_jira: 1.0.0
  • integration_twitter: 1.0.0
  • integration_whiteboard: 0.0.14
  • logreader: 2.6.0
  • lookup_server_connector: 1.9.0
  • mail: 1.10.1
  • metadata: 0.14.0
  • music: 1.2.1
  • nextcloud_announcements: 1.10.0
  • notes: 4.1.0
  • notifications: 2.9.0
  • oauth2: 1.9.0
  • onlyoffice: 7.0.2
  • password_policy: 1.11.0
  • photos: 1.3.0
  • privacy: 1.5.0
  • provisioning_api: 1.11.0
  • quota_warning: 1.10.0
  • ransomware_protection: 1.11.0
  • recommendations: 1.0.0
  • serverinfo: 1.11.0
  • settings: 1.3.0
  • sharebymail: 1.11.0
  • spreed: 11.3.1
  • support: 1.4.0
  • survey_client: 1.9.0
  • suspicious_login: 4.0.0
  • systemtags: 1.11.0
  • talk_matterbridge: 1.22.4
  • tasks: 0.13.6
  • text: 3.2.0
  • theming: 1.12.0
  • twofactor_backupcodes: 1.10.0
  • updatenotification: 1.11.0
  • user_status: 1.1.1
  • user_usage_report: 1.5.0
  • video_converter: 1.0.2
  • viewer: 1.5.0
  • weather_status: 1.1.0
  • welcome: 0.0.5
  • workflow_pdf_converter: 1.6.0
  • workflowengine: 2.3.0
    Disabled:
  • encryption
  • epubreader
  • files_external
  • user_ldap
</details>

<details><summary>Configuration (config/config.php)</summary>

{
“instanceid”: “REMOVED SENSITIVE VALUE”,
“passwordsalt”: “REMOVED SENSITIVE VALUE”,
“secret”: “REMOVED SENSITIVE VALUE”,
“trusted_domains”: [
oszproject.de”,
www.oszproject.de
],
“logtimezone”: “Europe/Berlin”,
“datadirectory”: “REMOVED SENSITIVE VALUE”,
“dbtype”: “mysql”,
“version”: “21.0.3.1”,
“overwrite.cli.url”: “https://oszproject.de”,
“dbname”: “REMOVED SENSITIVE VALUE”,
“dbhost”: “REMOVED SENSITIVE VALUE”,
“dbport”: “”,
“dbtableprefix”: “oc_”,
“mysql.utf8mb4”: true,
“dbuser”: “REMOVED SENSITIVE VALUE”,
“dbpassword”: “REMOVED SENSITIVE VALUE”,
“installed”: true,
“default_language”: “de”,
“default_locale”: “de_DE”,
“trashbin_retention_obligation”: “30,90”,
“onlyoffice”: {
“verify_peer_off”: true
},
“mail_smtpdebug”: true,
“integrity.check.disabled”: true,
“memcache.local”: “\OC\Memcache\APCu”,
“memcache.distributed”: “\OC\Memcache\Redis”,
“filelocking.enabled”: true,
“memcache.locking”: “\OC\Memcache\Redis”,
“redis”: {
“host”: “REMOVED SENSITIVE VALUE”,
“port”: 6379,
“timeout”: 0
},
“maintenance”: false,
“theme”: “”,
“loglevel”: 2,
“updater.release.channel”: “stable”,
“app_install_overwrite”: [
“social”,
“bruteforcesettings”
],
“mail_smtpmode”: “smtp”,
“mail_sendmailmode”: “pipe”,
“default_phone_region”: “DE”
}

</details>

**External storages:** files_external is disabled

**Encryption:** no

**User-backends:** 
 * OC\User\Database


**Browser:** Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:90.0) Gecko/20100101 Firefox/90.0


I have reset BigBlueButton back to version 2.3.9. Now it works again. The error is apparently due to incompatibility with version bbb 2.4 beta-1.