Deleting files from Live projects or re-importing them - how can I do that?

Finally, finally, I get around to trying out Trados Live (Essential).

First problem: I created a project, but because I did not import a customized Embedded Content Processor, one of the files was not converted to translatable format. I can't get it out of the "error" stage now. I added the ECP settings, but I can't make Trados Live to re-process the file with the now-complete file type definition.

I also can't delete the file, nor can I update it. (Or I have not found out how, which is probably more likely.)

What am I doing wrong, and how can I make this work?

Thank you in advance,