Opening and ending tag mismatch

Hope you all had a lovely Christmas/holiday break.
I’ve previously succeeded in compiling to epub in Scrivener for Windows and published/sold copies without any problems, but my latest attempt, when exporting the file from Dropbox and opening in iBooks, gives the following error message:
“error on line 30 at column 250: Opening and ending tag mismatch: ul line 0 and td”

I’ve Googled it but all the articles I see assume that you know how to write code, and I don’t. I’ve searched the Forum here but the only example related to someone with endnotes which they deleted and replaced - I don’t have endnotes. There are no strange symbols in my MS or anything in this section that doesn’t appear elsewhere in the MS. I’m not sure how to tell which line and column the numbering refers to, otherwise I’d delete and retype it to see if that made a difference.

Any ideas how can I resolve it please?