Today I have imported from Pubmed two entries (ID: 2974034 and 27623067). I failed the pdflatex compilation with an error. It took me a while to notice that the abstract had % signs in it which were no changed to %. This has not happened in a long time. Is this a bug?
Thanks for your report!
I can confirm this and as far as I know there was no change to that. But I remember that I once had similar problems with an older JabRef version.
Would you please be so kind and open an bug report at github? https://github.com/JabRef/jabref/issues