@Coriandre According to the explanation on
Crinrict's site, igs.bin stores login data for the store, and platform.bin some info about your system. I guess if either one becomes corrupted, it's easy to see how the store content would stop working, especially since store content is encrypted.
Why the files are getting corrupted, or their info doesn't match what's on file, over and over, I don't know. A random guess would be that someone's antivirus is flagging some activity that involves those files, for example when the launcher opens and connects to EA servers, some data passes back and forth. But since I don't have the issue myself, it's hard to test.