Version information:

JabRef 3.8.2
windows 10 10.0 amd64 
Java 1.8.0_121

Steps to reproduce:

1. Open database properties dialog, and Click Enable saving actions.
2. Using Tasks Manager in Windows 10, you will see JabRef costing a high quota of CPU, esp. higher than 30% for my laptop.
3. The directory contains the BibTex file will continuously generate new *.sav.log file and delete it again and again.
4. When open the error console, there is nothing in the Exception tab.

Only one log of opening my database found in the error console

20:15:08.224 [AWT-EventQueue-0] INFO  net.sf.jabref.logic.importer.OpenDatabase - Opening: D:\git\JabRefBibs\MyFullResearch.bib

Additionally, when I disabled the saving actions, everything becomes still at once.