"Invalid Class" Error when creating a new backup

See below screenshots of errors and log entries
screenshot of error
screenshot of log

About -> System Properties info:
APIVersion : 1
PasswordPlaceholder : **********
ServerVersion : 2.0.4.23
ServerVersionName : - 2.0.4.23_beta_2019-07-14
ServerVersionType : Beta
StartedBy : Tray icon
BaseVersionName : 2.0.4.23_beta_2019-07-14
DefaultUpdateChannel : Beta
DefaultUsageReportLevel : Information
ServerTime : 2019-12-05T23:07:28.605908-07:00
OSType : Windows
DirectorySeparator :
PathSeparator : ;
CaseSensitiveFilesystem : false
MonoVersion :
MachineName : x
UserName : x
NewLine :
CLRVersion : 4.0.30319.42000
CLROSInfo : {“Platform”:“Win32NT”,“ServicePack”:"",“Version”:“10.0.17134.0”,“VersionString”:“Microsoft Windows NT 10.0.17134.0”}
ServerModules :
UsingAlternateUpdateURLs : false
LogLevels : [“ExplicitOnly”,“Profiling”,“Verbose”,“Retry”,“Information”,“DryRun”,“Warning”,“Error”]
SuppressDonationMessages : false

ommitted for privacy

BrowserLocale : {"Code":"en-US","EnglishName":"English (United States)","DisplayName":"English (United States)"}
SupportedLocales : [{"Code":"bn","EnglishName":"Bangla","DisplayName":"বাংলা"},{"Code":"ca","EnglishName":"Catalan","DisplayName":"català"},{"Code":"cs","EnglishName":"Czech","DisplayName":"čeština"},{"Code":"da","EnglishName":"Danish","DisplayName":"dansk"},{"Code":"de","EnglishName":"German","DisplayName":"Deutsch"},{"Code":"en","EnglishName":"English","DisplayName":"English"},{"Code":"es","EnglishName":"Spanish","DisplayName":"español"},{"Code":"fi","EnglishName":"Finnish","DisplayName":"suomi"},{"Code":"fr","EnglishName":"French","DisplayName":"français"},{"Code":"hu","EnglishName":"Hungarian","DisplayName":"magyar"},{"Code":"it","EnglishName":"Italian","DisplayName":"italiano"},{"Code":"ja-JP","EnglishName":"Japanese (Japan)","DisplayName":"日本語 (日本)"},{"Code":"ko","EnglishName":"Korean","DisplayName":"한국어"},{"Code":"lt","EnglishName":"Lithuanian","DisplayName":"lietuvių"},{"Code":"lv","EnglishName":"Latvian","DisplayName":"latviešu"},{"Code":"nl-NL","EnglishName":"Dutch (Netherlands)","DisplayName":"Nederlands (Nederland)"},{"Code":"pl","EnglishName":"Polish","DisplayName":"polski"},{"Code":"pt","EnglishName":"Portuguese","DisplayName":"português"},{"Code":"pt-BR","EnglishName":"Portuguese (Brazil)","DisplayName":"português (Brasil)"},{"Code":"ro","EnglishName":"Romanian","DisplayName":"română"},{"Code":"ru","EnglishName":"Russian","DisplayName":"русский"},{"Code":"sk","EnglishName":"Slovak","DisplayName":"slovenčina"},{"Code":"sk-SK","EnglishName":"Slovak (Slovakia)","DisplayName":"slovenčina (Slovensko)"},{"Code":"sr-RS","EnglishName":"Unknown Locale (sr-RS)","DisplayName":"Unknown Locale (sr-RS)"},{"Code":"sv-SE","EnglishName":"Swedish (Sweden)","DisplayName":"svenska (Sverige)"},{"Code":"th","EnglishName":"Thai","DisplayName":"ไทย"},{"Code":"zh-CN","EnglishName":"Chinese (Simplified, China)","DisplayName":"中文(中国)"},{"Code":"zh-HK","EnglishName":"Chinese (Traditional, Hong Kong SAR)","DisplayName":"中文(香港特別行政區)"},{"Code":"zh-TW","EnglishName":"Chinese (Traditional, Taiwan)","DisplayName":"中文(台灣)"}]
BrowserLocaleSupported : true
backendgroups : {"std":{"ftp":null,"ssh":null,"webdav":null,"openstack":"OpenStack Object Storage / Swift","s3":"S3 Compatible","aftp":"FTP (Alternative)"},"local":{"file":null},"prop":{"s3":null,"azure":null,"googledrive":null,"onedrive":null,"onedrivev2":null,"sharepoint":null,"msgroup":null,"cloudfiles":null,"gcs":null,"openstack":null,"hubic":null,"amzcd":null,"b2":null,"mega":null,"box":null,"od4b":null,"mssp":null,"dropbox":null,"sia":null,"jottacloud":null,"rclone":null}}
GroupTypes : ["Local storage","Standard protocols","Proprietary","Others"]
Backend modules: aftp amzcd azure b2 box cloudfiles dropbox file ftp googledrive gcs hubic jottacloud mega msgroup onedrive onedrivev2 sharepoint openstack rclone s3 od4b mssp sia ssh tahoe webdav
Compression modules: zip 7z
Encryption modules: aes gpg
Server state properties
lastEventId : 88
lastDataUpdateId : 4
lastNotificationUpdateId : 0
estimatedPauseEnd : 0001-01-01T00:00:00
activeTask :
programState : Running
lastErrorMessage :
connectionState : connected
xsfrerror : false
connectionAttemptTimer : 0
failedConnectionAttempts : 0
lastPgEvent :
updaterState : Waiting
updatedVersion :
updateReady : false
updateDownloadProgress : 0
proposedSchedule : []
schedulerQueueIds : []
pauseTimeRemain : 0

Welcome!

Does the error ‘invalid class’ appear immediately after you click Add Backup and then click Next (for Configure a New Backup)? Or do you have to change something on that screen to make it pop up?

If you have never used Duplicati before, can you try using the latest Canary version to see if it has the same problem?

Resolved by upgrading I believe. Thank you and sorry for the late reply.

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