I have been having this issue i cant figure out. when i download to the HMI PC i often get this warning/error that cancels the download. it does not say anywhere what this precondition is. If I compile it does not show any errors. the weird part is it does not always happen. often if I retry the download multiple times on the 3rd or 4th it will work.

I have tried compiling software and software rebuild all. I have downloaded through the extended download to device function or with the download button. I have shut down the HMI to download and I have also left it open. the only thing I have noticed is if I close TIA portal completely the very first download when I reopen it always works.

Hi,

My first check would be to verify that the points in the FAQ below are fulfilled in your case:

What should you watch out for when downloading WinCC Runtime Professional from the Engineering Station to the Operator Station (Runtime PC)?