Thanks for help in Advance guys. 

Here is my scenario.

We are on OS11 and we have a timer which connects to a shared network folder (hosted on our internal network and managed by different team) to get a csv file and process it further. To connect to the shared folder we are using FileSystem forge component. Functionality was working all this time and it suddenly not working from last 2 days. And I am trying to understand what changed. 

This is what I have tried so far.

1. Service account which we use to connect to shared folder, is connecting fine And I verified that by mapping network drive or also by going to shared folder url with same service account credentials. I can see complete folder structure and files under it when I do that.

2. I tried passing path to the directory, domain name, username and password parameters to Directory_Exists function and Directory_Exists.Exists returns false with blank error message And  I confirm manually that there are directories under network path.

3. I tried passing  path to the file (including filename), domain name, username and password parameters to File_Exists function with the same results. File_Exists.Exists returns false with blank error message.

Since the error message doesn't say anything I am not sure if its having problem connecting to path or not able to see directories and files under it. Our Infrastructure management team says Service account has full access to all the directories and files under the network path. 

Can you please suggest what am I missing?

Thanks for your help again.