That is not the error dialog at export. To ignore this dialog just click OK. But I do not understand why people keep asking what to do on this dialog when it tells right at the top!
I understand your frustration. Now that I re-read your original reply, I realize the “ignore” button would appear on the export window, not on this one.
With all due respect, if the message at the top “double click each row to locate a file” is the one you mean, perhaps it’s not as helpful when the file has been deleted. And that “OK” is the proper choice in that case. That the Export window will provide a workaround maybe is not as clear at the time this window appears. But that’s just me.
Because the file name that was missing was the one I wanted to create in that folder, I created another folder, restored the original mp4 from the recycle bin and and moved it into that new folder, then used the locate in folder option. (Then removed it via Playlist. I had no further issues). I’ll know better if there is a next time.
Others have had success pointing to any file on their system, a file never used in the project, and then proceeding past the ugliness of that ugly duck in the project by immediately deleting (INSIDE Shotcut) that file from the Timeline and the Playlist, then moving on.