1000 line note limit

I went to save a text file. In Bitwarden I created a folder, made settings to save a note and cut and pasted the contents of the note into the Bitwarden note field. Bitwarden says its in excess of the 1000 line limit. My text editor says it is 868 lines in length, total. I went and checked and the file properly ends after the end of the text. No hidden white space etc…
So how do I fix this?

The size limits are calculated after encryption, which expands the size somewhat.

Hello @Slinkr and welcome to the community,

Is the Secure Note you are trying to create 868 characters or lines? You also mentioned the error said 1000 line limit when the character limit I understand is 10,000 characters.
Though as a note, as Grb mentioned the field limit is imposed after encryption, so the true limit is typically closer to ~50-85%

See more here,

On import, the character count of any given field is increased due to encryption, meaning that an 8000-character Notes field in your .csv will scale to 10,000+ characters when it comes into contact with Bitwarden, triggering this error. As a rule of thumb, character counts will grow between 30-50% when encrypted.

Get Premium, then you will be able to attach the text file itself to any vault item.