The "ULTRA-THIN" BONE-DRY PLUS formula is an outstanding performer but it has one quirk: it crystallizes with prolonged exposure to temperatures below 45°F. This probably will not occur at your location but it might occur in shipping along the way to your place.
If this does occur, it will look like the resin has gone clumpy, like crystallized honey. The remedy; same as honey, pop the entire bottle into a microwave oven and nuke it for about 10 seconds. Depending on your microwave, it might take two or three sessions to bring it back to its liquid state again. It might need to get to a temperature of 125°F - right about where the bottle feels hot but not too hot to hold.
Once this has been achieved, the resin is perfectly good again and can be used and it will stay like this for years. If the resin is exposed again to a temperature of under 45°F for a few hours, it will crystallize again. The same remedy will fix it.