I am experiencing a persistent issue across all my SharePoint 2013 workflows that use Plumsail Actions (specifically "HTML to PDF" and "Call Service"). The workflows are getting suspended with a "Retry" status and the following error:
CSP Check: We have already enabled -DelayContentSecurityPolicyEnforcement $true at the Tenant level.
Permissions: Sites have DisableAppViews and DisableFlows set to NotDisabled.
Workflow History: We noticed the error occurs when the workflow tries to write the service response or error logs into the SharePoint list/history.
Observation: The document generation does not complete, and the workflow hangs in a retry loop.
Question: Is there a recent change in the Plumsail API response format or metadata that might be exceeding the 255-character limit of standard SharePoint text fields or containing characters (like \u000a) that SharePoint Online's modern validation now rejects?
I would appreciate any guidance on how to fix this "Invalid text value" conflict that is preventing the workflows from completing the item updates.
I would like to confirm that I have already performed the steps you mentioned:
I added https://*.plumsail.com and https://*.spform.com to the Trusted Script Sources under the SharePoint Admin Center (Advanced > Script sources).
I also updated the HTML Field Security at the site collection level to allow these domains.
Additionally, I ran the PowerShell command Set-SPOTenant -DelayContentSecurityPolicyEnforcement $true and verified it is active.
Despite these changes, the workflow still hangs in a retry loop with the following error: "HTTP InternalServerError (500) ... Invalid text value. A text field contains invalid data."
It seems the workflow is unable to complete the document generation or handle the response correctly, and it fails when trying to log the error/response into the SharePoint Workflow History (exceeding the 255-character limit because of the detailed technical error).
Could there be any other underlying issue related to the March 2026 Microsoft updates on Custom Scripting (DenyAddAndCustomizePages) that might be interfering with how Plumsail Actions communicate with the SharePoint API?
Invalid text value. A text field contains invalid data.
So the failure appears to happen when the workflow tries to write a value back to SharePoint, not when Plumsail actions are loaded.
Most likely, one of the workflow steps is trying to store a long response or error message into a SharePoint field that accepts only a short text value, for example a single line of text or workflow log entry. This would also match the retry loop behavior if the workflow keeps attempting the same update.
I’d suggest checking these points:
Review any workflow step that writes the output of HTML to PDF, Call Service, or an error variable into SharePoint.
If that value is written to a single line of text field or to the workflow history/log, try replacing it with a short static value first, for example: Test.
If that works, then the issue is likely the actual response/error text length or content.
Try truncating the logged value before writing it back, or store it in a multiple lines of text field instead of a single line field.
