This issue occurs when the user running the merge action does not have access to one or more fields used in the underlying report. Although the error message suggests a template or server issue, it is often misleading. The merge process fails before generating the document, so the system cannot find a valid DOCX file to convert into a PDF, resulting in the “Cannot find parameter 'docx'” error.
In this case, the merge worked for users with broader access (like System Administrators), but failed for a specific user because they were missing permission to a field included in the report. Since Apsona relies on the report data to generate the document, missing field access prevents the document from being created altogether.
To resolve this, ensure that the end user:
Has access to all fields used in the report (both in Salesforce profile/permission sets and Apsona configuration)
Has access to the Documents object required for merge operations
Even if the error appears to be related to the template or server, always verify user permissions first. Missing access to any field in the report can cause the merge to fail and trigger this error.