Help solving Red Javascript error sjcl is not defined

TiddlyWIki 5.3.2 on FireFox and Chrome

I have a wiki full of experiments, of quite some value to me, and possibly the community. For some reason when I click the + new tiddler, or edit an existing tiddler I get the following red warning, and an untitled tiddler card appears above in the story.

Internal JavaScript Error
Well, this is embarrassing. It is recommended that you restart TiddlyWiki by refreshing your browser
ReferenceError: sjcl is not defined
Close

sjcl has come up before with empty filter but I am trying to identify the cause, any one seen this recewnly?

I’m pretty sure that’s the encryption library. Wild guess… it sounds like it thinks the tiddler needs decrypting?

maybe tiddler $:/library/sjcl.js has been deleted?

Thanks @buggyj I looked for that tiddler $:/library/sjcl.js, never remembering any use for it, it was missing, dragged a copy from tiddlywiki.com save and reload, preliminary testing suggests its fixed.

Is that the only tiddler required that does not have a shadow copy?

:clap: thanks so much

Also the boot js and css files