When you delete a resource pack you used lately, Minecraft does not update the options.txt file causing crash reports to contain wrong information.
- Download the attached resource pack
- Load it in Minecraft
- Close Minecraft
- Delete the resource pack
- Open Minecraft again and close it (to make sure it did not remove the resource pack from the options.txt file)
- Open the options.txt file
→ You will see that the resource pack is still listed as active resource pack.