This might be related to WORDSNET-6397 and has been discussed here: https://forum.aspose.com/t/58200 related to v22.214.171.124
Image/html content controls work for some documents but fail to work on slightly different ones.
The error message is "Cannot insert a node of this type at this location". It works sometimes when adding the image/html content control inside a table cell, but sometimes - eg with a bit more complex documents - it throws the error.
Is that fixed in the more recent versions (we are using v126.96.36.199)?