I was experiencing the error "invalid signature" about a year ago. A simple "read" or "write" or "list" task would fail with the error message "invalid signature".

These tasks were defined with variables, in the path field

Example, a read task, would have a few variables for the directory path of the file to be read... \\ variable1.variable2\\variable.txt

I thought I solved the mystery of the "invalid signature", when i saw a correlation with "event" triggers. I have a number of jobs which use the event trigger. Example, event trigger when a job is deactivated. I increased the polling frequency...and this appeared to fix the invalid signature problem. Note, the event triggers were being used on jobs that did not experience the invalid signature problem. But it appeared it affected other jobs (these other jobs which did not use the event trigger) experienced the "invalid signature" problem.

I have about 200 to 280 Visualcron jobs per server. I'm running a mix of Windows 10, Windows 7 and Windows 2012R2.

Can i get a clear explanation as to what the error message "invalid signature" means.