Error: Invalid URI: The format of the URI could not be determined. in task

Is this a custom task or a Kentico default task? Where do you see this error? Any other information in the eventlog...

Hello David,

This is my custom task and i am not getting any error in Event log.

Well you could wrap your entire custom task in a try/catch block to at least catch the error.

So what logic are you using in your code that does something with an "uri property".

probably you something like

Uri myURL = new Uri(myUrlProperty);

where the value of myUrlProperty is invalid.