Summary of the problem RFTools Builder showing "Chunk not available" error, even when all appropriate chunks should be loaded (mistyped the title a little) Pack Version 1.8.0 What is the bug? I recently took a break from playing this pack for a time, and even before that break (pack version being earlier), I've had this error message on my Builders from time to time: "Chunk not available." This has prevented me from quarrying consistently and smoothly as whenever I manage to clear the condition from the machine (via support mode activation or deactivation), the Builder only mines for a few more minutes to an hour. Before taking my break from Minecraft, I mostly experienced this error in the nether and nowhere else... Now, I'm seeing the error in one of my four RFTools dimensions on three of my four Builders running there (I mine a TON of blocks from those). As this dimension is my main source of coal (being made of whole blocks of the stuff), this creates a serious crimp in my energy supply lines. I've ensured that my config files facilitate the loading of chunks as the Builder works. I've placed a ChickenChunks spot loader where the Builder stands. I've made sure that the Builder has enough power at most any given time and has an inventory placed on top to collect what's mined... The error still occurs time and again, and only on my quarry Builders, not the ones fitted with pump cards (for oceans of lava). I haven't had this problem with quarry Builders set up in the overworld, only in alternate dimensions. Also, I've experienced this error with both clearing and normal quarry cards. I've done everything short of loading every single possible chunk my quarries could mine in their maximum areas via other means such as ChickenChunks, but nothing seems to alleviate this error for more than an hour. I've explored each area thoroughly to generate each respective chunk, but the error still occurs. It hasn't yet caused a crash (although traveling too fast through my dimensions has on occasion), but being an error, I still suspect this to be against mod developer wishes for intended game-play. If anyone has a suggestion or knows a solution I haven't yet tried, please tell me. Otherwise, it may be best to suggest a fix to this great mod's developer, and I would like to know where to place one of those. Mod & Version RFTools, version 1.12-7.24 (and various earlier versions from the Direwolf20 1.12 pack) Link to log file Is it repeatable? No. It has only happened to me randomly while using the specified machine in the widest possible area and specified settings with inconsistent results. While trying to repeat this error in other areas or worlds, I found it impossible. Known Fix Temporarily, it is possible to use the support/guide mode of the Builder to force the machine to continue operation (toggling this mode on and off)... but this only lasts a few minutes to an hour at a time, without losing quarry progress.