OWA 2013 blocks XML attachments

Hello. I have a common problem about blocking xml files in Exchange 2013 SP1 OWA.

I have allowed xml in owamailboxpolicy and owavirtualdirectory. I have removed xml from blockedfiletypes but still i can't save or open xml in owa.

Can anyone tell me why?

[PS] C:\Windows\system32>Get-OwaMailboxPolicy -identity default |fl *allow*, *block*


AllowedFileTypes : {.rpmsg, .xlsx, .xlsm, .xlsb, .tiff, .pptx, .pptm, .ppsx, .ppsm, .docx, .docm, .zip, .xml, .xls, .wmv, .wma...}
AllowedMimeTypes : {application/xml, image/jpeg, image/png, image/gif, image/bmp, text/xml}
AllowOfflineOn   : AllComputers
BlockedFileTypes : {.vsmacros, .msh2xml, .msh1xml, .ps2xml, .ps1xml, .mshxml, .gadget, .mhtml, .psc2, .psc1, .msh2, .msh1, .aspx, .wsh, .wsf, .wsc...}
BlockedMimeTypes : {application/x-javascript, application/javascript, application/msaccess, x-internet-signup, text/javascript, application/prg, application/hta, text/scriplet}



[PS] C:\Windows\system32>Get-OwaVirtualDirectory |fl *allow*, *block*
(you can't see xml in allowedfiletypes i've added it there)

AllowedFileTypes              : {.rpmsg, .xlsx, .xlsm, .xlsb, .vstx, .vstm, .vssx, .vssm, .vsdx, .vsdm, .tiff, .pptx, .pptm, .ppsx, .ppsm, .docx...}
AllowedMimeTypes              : {image/jpeg, image/png, image/gif, image/bmp}
RemoteDocumentsAllowedServers : {}
AllowOfflineOn                : AllComputers
BlockedFileTypes              : {.vsmacros, .msh2xml, .msh1xml, .ps2xml, .ps1xml, .mshxml, .gadget, .mhtml, .psc2, .psc1, .msh2, .msh1, .aspx, .wsh, .wsf, .wsc...}
BlockedMimeTypes              : {application/x-javascript, application/javascript, application/msaccess, x-internet-signup, text/javascript, application/prg, application/hta, text/scriplet}
RemoteDocumentsBlockedServers : {}