Broken Cache after Android 6.0 Upgrade

Hi guys!

We have a strange issue with our Unity 5.2.4f1 Android builds. If the game was played on older Android and was then upgraded to Android 6.0 (via OTA update; reported on many nVidia Shield Tablets and recently Samsung Galaxy S6 and S6 Edge, since the updates started to roll out).

After the upgrade, the cache gets corrupted and all static objects (lightmapped) load in pitch black, with no textures on it. Characters, particles and GUI Sprites are not affected, but the rest of scene is missing.

It does help to clear cache within Application Info, but I have no clue whether it is possible to clear it from within Unity, since it is not that easy to explain the process to casual Android users. According to documentation, Caching.ClearCache only affect AssetBundles and Procedural Materials, so it seems like a no-go, since we don't use any of those (unless, of course, AssetBundles also include the monolithic OBB file). Also, I have no clue on how often is it safe to clear the cache without affecting performance. Does anybody have any ideas or solution for that?

Thank you very much!