I just had this issue with in RW 7.5.1.
I have a fully published operational website that I only made some tweaks to last night and now it won’t publish. Minify CSS was already turned off, so that solution did not resolve anything.
I have read the thread and I am trying to publish one page at a time. This works. BUT, after I went down the whole list of pages and finally got to the Sitemap page, when I published that, it put blue dots on all the pages I just tediously uploaded one at a time and now I am doing that process all over again. Anyone else doing this, I suggest you start with the Sitemap page first before uploading every other page.
SIDENOTE: Why does the contact page have 158 elements that have to be uploaded when all my other pages average around 20 elements? That seems excessive for such a simple form page.
After doing publishing each page seperately, I saved the file, then made a copy. I made minor changes on the copy and did a regular full publish of the site and it seemed to work normal.
I also use Meta Mate stack. Making a change in Meta Mate prior to publishing last night might have caused this error, but I am not sure. I just made a change in on a page in Meta Mate which affected all the pages, causing me to do a new full upload, but no problems. The full site uploaded.