diff --git a/src/pocketmine/level/format/io/region/RegionLoader.php b/src/pocketmine/level/format/io/region/RegionLoader.php
index decb9c1c5..042852c65 100644
--- a/src/pocketmine/level/format/io/region/RegionLoader.php
+++ b/src/pocketmine/level/format/io/region/RegionLoader.php
@@ -142,13 +142,13 @@ class RegionLoader{
 			if($length >= self::MAX_SECTOR_LENGTH){
 				$this->locationTable[$index][0] = ++$this->lastSector;
 				$this->locationTable[$index][1] = 1;
-				throw new CorruptedChunkException("Corrupted chunk header detected (sector count larger than max)");
+				throw new CorruptedChunkException("Corrupted chunk header detected (sector count $length larger than max " . self::MAX_SECTOR_LENGTH . ")");
 			}
 			return null;
 		}
 
 		if($length > ($this->locationTable[$index][1] << 12)){ //Invalid chunk, bigger than defined number of sectors
-			MainLogger::getLogger()->error("Corrupted bigger chunk detected (bigger than number of sectors given in header)");
+			MainLogger::getLogger()->error("Chunk x=$x,z=$z length mismatch (expected " . ($this->locationTable[$index][1] << 12) . " sectors, got $length sectors)");
 			$this->locationTable[$index][1] = $length >> 12;
 			$this->writeLocationIndex($index);
 		}
@@ -240,6 +240,16 @@ class RegionLoader{
 		return $x | ($z << 5);
 	}
 
+	/**
+	 * @param int $offset
+	 * @param int &$x
+	 * @param int &$z
+	 */
+	protected static function getChunkCoords(int $offset, ?int &$x, ?int &$z) : void{
+		$x = $offset & 0x1f;
+		$z = ($offset >> 5) & 0x1f;
+	}
+
 	/**
 	 * Writes the region header and closes the file
 	 *
@@ -265,18 +275,23 @@ class RegionLoader{
 		}
 
 		$data = unpack("N*", $headerRaw);
+		/** @var int[] $usedOffsets */
 		$usedOffsets = [];
 		for($i = 0; $i < 1024; ++$i){
 			$index = $data[$i + 1];
 			$offset = $index >> 8;
 			if($offset !== 0){
-				fseek($this->filePointer, $offset << 12);
+				self::getChunkCoords($i, $x, $z);
+				$fileOffset = $offset << 12;
+
+				fseek($this->filePointer, $fileOffset);
 				if(fgetc($this->filePointer) === false){ //Try and read from the location
-					throw new CorruptedRegionException("Region file location offset points to invalid location");
+					throw new CorruptedRegionException("Region file location offset x=$x,z=$z points to invalid file location $fileOffset");
 				}elseif(isset($usedOffsets[$offset])){
-					throw new CorruptedRegionException("Found two chunk offsets pointing to the same location");
+					self::getChunkCoords($usedOffsets[$offset], $existingX, $existingZ);
+					throw new CorruptedRegionException("Found two chunk offsets (chunk1: x=$existingX,z=$existingZ, chunk2: x=$x,z=$z) pointing to the file location $fileOffset");
 				}else{
-					$usedOffsets[$offset] = true;
+					$usedOffsets[$offset] = $i;
 				}
 			}