We recently deployed the Workflow Manager in SharePoint 2019 farm. After we deployed the April 2020 CU, the SharePoint 2013 style workflows were getting stuck on starting with the following error.
System.Net.WebException: The request was aborted: The request was canceled. —> System.InvalidOperationException: None of the trusted issuers specified by the server’s 401 challenge match the client’s known issuer ‘00000005-0000-0000-c000-000000000000@e2a61c0c-7b9c-4095-a643-554242c8cb17’. For reference, the following trusted issuers were returned by the server: 00000005-0000-0000-c000-000000000000*, 00000003-0000-0ff1-ce00-000000000000@e2a61c0c-7b9c-4095-a643-554242c8cb17.
The root cause of this error is incorrect RegisteredIssuerName in the SPTrustedSecurityTokenIssuer.
To resolve this issue,
Start the SharePoint 2019 Management Shell using the Farm account
Find the id of the existing SPTrustSecurityTokenIssuer using the cmdlet Get-SPTrustedSecurityTokenIssuer
In the output, we need to look for the token issuers with the DisplayName as “00000005-0000-0000-c000-000000000000”. Copy the id which will be below the DisplayName
Remove the existing SPTrustSecurityTokenIssuer using cmdlet Remove-SPTrustedSecurityTokenIssuer -Identity “Id we got in the step 2”
Register new SPTrustSecurityTokenIssuer using the cmdlet
If you are using https then
New-SPTrustedSecurityTokenIssuer -Name “00000005-0000-0000-c000-000000000000” -MetadataEndPoint ‘https://workflowmanagerservername:12290/$System/$Metadata/json/1’ -RegisteredIssuerName “00000005-0000-0000-c000-000000000000@*”
If you are using http then
New-SPTrustedSecurityTokenIssuer -Name “00000005-0000-0000-c000-000000000000” -MetadataEndPoint ‘http://workflowmanagerservername:12291/$System/$Metadata/json/1’ -RegisteredIssuerName “00000005-0000-0000-c000-000000000000@*”
Terminate the existing instance of the SharePoint 2013 styles workflows and re-run them.
You can find detailed information about this issue and it’s resolution here. https://techcommunity.microsoft.com/t5/sharepoint-support-blog/sharepoint-2019-issue-with-sharepoint-2013-workflows-post-april/ba-p/1440656