>>If I was your user, I'd be completely confused. I would had thought the thing that gives me the message is an application, but now it doesn't mention an application but rather an "application". For all the experience and million of double entendres that I've encountered so far, I still can't imagine what would be the other meaning of application that would be denoted by quotation marks.
>>
>>Was I "clear"?
>
>I simply meant that the word "application" will be replaced with the actual application name. For example Microsoft Word. More "clear" now?

Like this?

"Cannot open Parts (or another window) Windows because your computer lost connection to the
network/server.  Please close the <app name here> and open it again right away or in a minute"

Now the message sounds fine, not ambiguous (apart from writing Windows in propercase, which may be confused with something resembling an OS, or may be confused on its own). If I was your user, however (emphasizing the I), I'd ask
- why? Can't it reconnect?
- why restart, oh where's my gosh, this is as if it was written by M$ itself, there are certain things it can't do twice, you have to get out and come back in.
- why do I have to restart it? Can't it do that automagically, by itself? You know, as if it were something on a computer, computers know how to do things without me having to press too many buttons. They call that automati(zati)on.