Created Unassigned: Cannot create a file when that file already exists [100]

Clearscript 5.3.11.0 return error "Cannot create a file when that file already exists".

My project is an Windows application in C#, framework 4.5.
In the application each 1/2 seconds is called :

VBScriptEngine engine = new VBScriptEngine();
foreach (ParsedItem pi in _parsedItems) engine.AddHostObject(pi.Id, pi);
engine.Dispose();

The application is run in multiple instance (20 applications contemporary).
Sometimes in the log I get error "Cannot create a file when that file already exists".