[ikopcanski]

Hello, I have resolved this myself. The problem was probably related to max upload file size.
When I set .user.ini in root of WP site with adjusted file size, I opened dashboard in another window
(triggering new PHP process) and I successfully installed the parent and child theme.
I discovered this by uploading some other free theme and message was clear:
“…file size exceeds the one specified in php.ini file bla bla…”
maybe you can work on NOT hiding the correct error message while installing your theme.

I have also got some error while installing ‘I recommend this’ plugin that may be related to the problem,
but I am not sure about this.