datapack validation failed

recently I added some function commands and loot tables to my datapack,but now it stopped working entirely. It can't be validated on the datapack loading screen and on the log it said
''[18:18:14] [Render thread/WARN]: Failed to validate datapack
java.util.concurrent.CompletionException: java.lang.ArrayIndexOutOfBoundsException: Index 0 out of bounds for length 0'' 
I've deleted anything related to the function bt it still shows that,I'm frustrated. Any help will never go unnoticed and will be very appreciated