My "review" says I need to put an amount in the box for "misc exp other" on my Schedule C (for lyft/uber rideshare), but everything looks right.

You may have entered a miscellaneous expense but not entered an amount for it. It may have been something carried over from the previous year. A quick solution would be to enter $0 for the amount. Your other option would be to go back through your business expense entries and delete the expense account name that is there in error.