The caller with the number +6421700701 has made contact, but the nature and purpose of this contact are unclear due to the recipient's phone rendering the messages as "Message cannot be displayed". This suggests a potential issue with compatibility, formatting, or encryption of the messages. Given the lack of information, it's difficult to determine the intent behind these messages, but it's possible that it could be a telemarketing or spam attempt. However, without more context, the true nature of the messages remains unknown.
I received two texts in quick succession, both appearing as "Message cannot be displayed" on my older phone, with no clue about the source.