Hi @Anonymous ,
Welcome to Microsoft Q&A forum and thanks for using Azure Services.
As I understand from the question, you have started getting Error in Pipeline which involves Copy Activity when it has been working fine before.
In order to troubleshoot, could you please do the following:
1). Check if the Source=Microsoft.DataTransfer.DataContracts
, is accessible?
Could you check if you can connect in ADF through the Linked Service and Dataset.
Even if this shows success, could you also please check the directory/folder is correctly pointed.
2). Secondly, try to clear data schema of source dataset.
3). Again, import schema, clear Mapping in Copy setting, import schema on Mapping of Copy.
Please try and let us know if this helps.
If not, please share more details about the pipeline configuration which will help us in reproducing the issue and investigate.
Thank you.