In the same place you dump errors, you can capture the data you used. Examine it. You probably have bad data. Note that some people use emojis and as an example, a lot of systems die when faced with them. Or the classic UTF-8 encoding error as one rogue character is included.
So next time you do an update, dump the corresponding data so you can see what is up with it. Pasting it into a character viewer often shows some bad data, even though to the eyes it looks OK.
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