Anurag,
Hi. In addition to our community member suggestion above (Thanks Bill and Sahil - we agree to their statement that you need not to put the actual file name), we see an SAP Incident ticket on this currently in our support system. As far as we know, the attach document in Work Manager 8.0 is based on custom (consulting driven design) based on Agentry's File System capability.
With this said, Work Manager 8.0 does not have attach document out of the box. This may mean that your project already had it pre-designed before by a consulting team (theory). So when you use the File System of Agentry (As defined in the agentry.ini), there is a chance that the Agentry.ini that you are using is an older version and may not be compatible with the SMP 3.0 version. Suggestion here is to recompile the agentry.ini using the newer editor to make sure that the FileSystem connection type is still valid. The guess here is that you may have errors showing up in the logs.
Again the theory we have here is:
You are using older Agentry.ini (published in older Eclipse Agentry - designed in pre-SMP 3.0 environment) and using it in SMP 3.0.
Another thing we have to say is please communicate with your AE on anything Attach Document with respect to WM 8.0 or higher. This way they can request a feature to be added to the product for your company. This is the best route to get it out of the box.
Regards,
SAP Mobile Support Team