Red Hex flag on MIDI track

Having a small problem that I can’t find any documentation for or any online posts about.

I have imported a midi file into Ardour and several of the tracks have a strange red box showing hex numbers. I’ve looked to see what these are and how to edit/delete them but can’t find any reference to them. Has anyone else come across these and can advise what they are and how to deal with them.

Screenshot at 2020-06-25 11-02-20
Many thanks

Midi SysEx:

Thank you Mikael. That was just the pointer I needed. Yes, I’m aware of SysExs I just didn’t recognise how Ardour presents them. I have edited out all the SysEx events using Rosegarden and reimported. All is fine. Many thanks

While you cannot edit SysEx in Ardour, deleting the message should be possible.

In internal-edit-mode (press ‘e’) shift + right-click on the message should do it.

(shift + right-click is the general delete operator in all of Ardour)

Nice tip. I can delete notes easily enough in internal edit mode but it doesn’t touch the sysex flag. Sorry.