DCP-o-matic

Hi, guys!
When I make a DCP. It's tell me about this
Еrror：Badly formatted colour tag_HFFFF. What happened?
Help, please. Thanks!

used DCPoMATIC 2.16.8 and 2.16.18.
Windows 10

p.s after update to 2.16.21 have: Еrror：Badly formatted colour tag \c

This tag \c is a bit of a mystery - is it possible to send the source file that you are using? Someone else has already seen it (unless you are the same person!)