WorkStation Application Setting:
To explain in simple term, this setting is necessary to allow your document type to attach documents of different extensions.
We will have business needs to attach document like .xls or .pdf or .jpg, in case if you have not maintained this setting then you will receive the below error.
File Extension XXX not allowed for the workstation application xxx.
Message no : 26504.
The below configuration will resolve this error:
Cross-Application Components>Document Management>General Data>Define Workstation Application
Do leave your comments if this was helpful or if you have additional questions on this topic