The meta.lsb file contains the level the characters are on. If a save is after Cyseal, this can cause problems if the location on that map is out of bounds on the Cyseal map. In that case (if the teleporter pyramids and/or Rift Travel can't help) you can load the old save, teleport to Cyseal re-save, extract the contents of that save and then replace the meta.lsb file there.
For the 'corrupt' message, try moving the lsv / lsv.bak file(s) to a different folder or subfolder, just leaving the screenshot, extracted files and folder, and the replacement meta.lsb file.