TM1 processes will not complain when their input source is empty.
So although the "process successful" or "chore successful" message will popup, your cube will remain desperately empty.
In order to solve that silent bug (or rather "feature" in IBM's eyes), you will need to add specific code to your TI processes to test against empty sources.
Here follows:

.initialise counter
PROLOG TAB

SLineCount = 0;

#****GENERATED STATEMENTS START****

.increment counter
DATA TAB

SLineCount = SLineCount + 1;

#****GENERATED STATEMENTS START****

.check counter value at the end and take appropriate action
EPILOG TAB

if(SLineCount = 0);
ItemReject('input source ' | DataSourceType | ' ' | DataSourceNameForServer | ' is empty!');
endif;

#****GENERATED STATEMENTS START****

ItemReject will send the error to the msg log and the execution status box will signal a minor error.