[ic] Strange ic behavior with png image usertag created

[marco]

With Variable DEBUG 1 in main configuration file interchange.cfg all 
goes well but without ic DEBUG 1 web browser give
Internal Server Error and apache error.log give this:

[Sat Dec 09 20:26:35.274482 2017] [http:error] [pid 680] [client 
192.168.11.2:58795] AH02429: Response header name 'libpng warning' 
contains invalid characters, aborting request, referer: ...

... to ic page from where i call the usetag that give the error.

Searching for this issue I have find this apache page:
https://blog.tigertech.net/posts/apache-cve-2016-8743/
that give responsability to malformed http header.

my enviro:
- Debian GNU/Linux 9
- Interchange V5.10.0
- perl 5.24.1

Any suggestions ?

P.S.
I try to attach the usertag and the complete url that give the error but 
mailer bounce back the message for suspicious header

-- 
"Fino alla bara sinpara"
"Up to demise we rize"