[Users] Zimbra 8.8.15 /service/proxy no longer works for Zimlets?

[Info Zeta Alliance]

Hello All, 

I used to be able to use /service/proxy to circumvent same-origin policy issues in Zimlet. 

Example I could: 
[ https://zcs-server.com/service/proxy?target=https%3A%2F%2Fnextcloud.com%2Fblogfeed%2F | https://zcs-server.com/service/proxy?target=https%3A%2F%2Fnextcloud.com%2Fblogfeed%2F ] 

No when I do that I get an error 500 and in the log a: 

/service/proxy 
java.lang.UnsupportedOperationException 

Is the proxy servlet killed in 8.8.15? 

Kind regards, 

Barry de Graaff 
Zeta Alliance 
Co-founder & Developer 
zetalliance.org | github.com/Zimbra-Community 

Signal: +31 617 220 227 
Fingerprint: 97f4694a1d9aedad012533db725ddd156d36a2d0 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.zetalliance.org/pipermail/users_lists.zetalliance.org/attachments/20190724/7d4c1e1d/attachment.html>