Clearstream projects issues

Hi, suddenly one of my CS projects stopped working. When I try to start the reader, says on Reader Status column: "Error. Failed to start reader". I have already tried removing and adding the reader to the project, as well as turning off / on the reader.

However, if I run another project that uses the same reader, works fine and the reader starts reading tags normally.

What could be the issue?

Thank you in advance for your help.