It's fine
Please take a look at device datasheet:
http://www.issi.com/WW/pdf/37-38SML01G1.pdfPage 11 - manufacturer guarantees 1004 valid blocks from 1024, so 1 faulty block is not bad
Pages 34-38 - you can read more about error management (it is similar in all NAND FLASH devices)
If block is faulty, then verification error at this block is normal. If you want to avoid verification error, then fill this block with zeros (all 0x00) - in your case it will be address range: 0x2420000 - 0x243FFFF and then verification will pass.
You may ask - what to do with data stored in this block? It depends. First of all check if your file (which you read at the beginning) stores any data in this block (maybe data is not stored there from the beginning and there is no problem). Secondly - if data is stored in this block - then all depends on hardware (host controller of NAND memory). You may copy this data to first empty (and valid) block. You may also shift all data with 1 block. NAND devices are not easy in management and it all depends on host controller which has implemented procedures for error and faulty blocks management. Good example are SSD drivers where you have also NAND memory arrays with single controller. You need to check specs of your hardware which option is recommended.