Hello,
The Product Library fails to read any manifest of S3A LST products. I get the following error message:
Product unreadable G:\Data\S3A\L2\S3A_SL_2_LST____20170730T023505_20170730T023805_20170730T042957_0179_020_260_2520_SVL_O_NR_002.SEN3\xfdumanifest.xml
Tested on both SNAP 5 and SNAP 6 Preview, with 23 different LST products from August to October 2017. On the other hand, I can view the product by opening the xfdumanifest.xml from File > Open Product.