Skype For Business SE - persistent Chat

Hello,

maybe someone of you run into the same error and is able to help me on this topic:

we are using SkypeForBusiness only for internal communication

last week we have upgraded SkypeForBusinness 2019 to SE: "SkypeServerUpdateInstaller.exe" run without errors, installed the necessary updates and we were able to upgrade to SE on topology builder and publish the new version.

on the next step we tried to activate persistent chat.

so same procedure for the upgrade: start the update file "PersistentChatUpateInstaller.exe", nothing else to upgrade

the first steps (install new sql instance, configure topology builder, publish the new topology were easy, no issues occured.

but when we start the Deployment Wizard to install the necessary components we received the error:

"File not found trying to install installing c:\programdata\skype for business server\deployment\cache\7.0.2046.0\setup\mgcserver.msi (feature_chat_server)"

my question:

how can we install the necessary roles/components to activate persistent chat.

the file MgcServer.msi couldn't be found on the server, i can't find it on the SkypeForBusinnes 2019 ISO, too.

one version i found, was located on the ISO for SkypeForBusiness 2015 ISO, but this version can't be installed.

Thanks in advance,

best regards,

Markus