Our client says it started to happen for more suppliers.

Our client "fixed" (not sure how) the note in MS word and copied back to the Note and it didn't crash anymore.
Before that it crashed with "too large or too small malloc: -1640328390" on opening the note.
An example note has 4299 chars and 115 lines.
Is there a limit for note size or, maybe, SERP does not like some characters which are used in MS Word?