The prospect fails on a sequence step, and the error shown is Missing template variable.
There are two potential resolutions, depending on which cause is affecting the prospect. The first, if a variable not being an Outreach variable, is to remove the incorrect variables or replace them with correct variables. The second, if the variable value is missing on the prospect, is to edit the prospect record so that the value can be pulled in by the variable. You can also remove the variable from the template.
There are two potential causes for this error. The first is that the variable on the template isn't an Outreach variable. In the screenshot above, that would be fake_variable_name. The second potential cause is that the variable doesn't have a value because that field isn't filled out on the prospect record. In the above screenshot, that would be company.