Infopath 2013 - cannot preview a form, cannot publish, cannot see what the error is

Question

First of all, I'm using Infopath 2013 in polish version, so the names of functions may be different.

Yesterday, I got an old Infopath 2013 file, which was migrated from 2010(at least collegue I got it from says so), including code but not documentation, which we are using in internal SPS. I was supposed to add one field and move on.

However, I can't even preview the file(file is unchanged). After some Googling I got some hints, that it may be due to file being copied&pasted and I follow tutorial on how to fix it - but to no effect.

There is an error message, yes. As you can see on image below, not even a little bit helpful. This error was sometimes related to code, but after setting breakpoint in code, nothing happens, as if it was never hit. Not even InternalStartup().

I tried moving everything to a folder with shorter path, publishing using settings[same(probably?) error as with preview], unlinking/removing code, checking the code, publishing elsewhere(no error, still cannot preview).

Did it happen anyone else, and what can I do to fix it?

Answer 1

Oh well...

Just a minute ago I stumbled into this: https://social.msdn.microsoft.com/Forums/en-US/abd2166b-a9ad-487e-bf83-8bb1d44ae7e5/error-infopath-cannot-open-the-selected-form-in-preview-mode-infopath-2007?forum=sharepointcustomizationlegacy

Which had solved my issue. I'm posting what was issue, if link would broke someday.

I found out that the URL in Tools-->Form Options-->Preview-->Domain was wrong/missing.

I've added the URL and - bam - it worked fine again.