I'll start by explaining the wording of this error message:
I figure the ACD workstation application here is AutoCAD. Assuming that's the case here, below is what the error means.
From the error in the document: "com.syclo.agentry.BusinessLogicException: AttachmentCaptureSteplet - File extension txt not allowed for workstation application ACD"
It seems you're attaching a wrong file type for the workstation application. The ACD workstation application should be for AutoCAD and will not be able to accept a text file with extension .txt
Please check with an Autocad document if that works.
Also please look through the link below:
for the section to manage the file format extensions.
> Go to transaction SPRO, Cross-Application Components -> Document Management -> General Data -> Define Workstation Application
> For each workstation application, make sure proper file extensions are maintained to upload/download files from the mobile client to/from the backend
> You will need to for maintain this file extension information