Opening data for the first time gets ignored

[Kenichi-Endo]

When I open a new instance of MetaConfigurator and open a random data or schema from the "open" button, nothing happens. Only after I do the same once again, does the data get imported.
My browser is Safari

[Logende]

this happens only sometimes. And can also happen multiple times in a row or not at all. I had already researched this and somehow the client does not detect the file open event sometimes. This needs some deeper debugging or an alternative way to handle the file upload.