Some issue is causing a timeout during access to the target computer file system.
While you are accessing the target computer file system to read or write a large data or log file, the connection between the development and target computer systems times out.
Increase the communication timeout value. If using file scopes, try using the Simulation Data Inspector instead to reduce file system I/O. If the file system access is failing during large file transfers, try using an FTP client for the transfer.