I did take care of other settings, so that they would be similar on both of the systems- but forgot about the most obvious one: the software that presents the export file
And so I took Notepad2 which I use on the desktop computer to the laptop- and immediately the bug showed up: Mp3tag kept popping questions but could not open a second instance of Notepad2. And so I kept seeing the same export results although the file itself with those results was changing its content- which I could check in ordinary Notepad by loading the export file to it after each execution of the Mp3tag export action. So the next logic thing was to do the opposite: revert from Notepad2 to ordinary Notepad on the desktop system- and immediately the bug was gone. So, is the Notepad2 the culprit? Not entirely. Because I started to test other pieces of software, designating them in the desktop's OS as the handlers of the TXT format, one by one
These do not manifest the bug [or "bug" to be more precise at this point of these revelations]:
- Notepad 6.1 Build 7601 (Service Pack 1)
- Notepad++ 6.7.9.2
- Adobe Dreamweaver CS4 10.0 Build 4117
- Firefox 56.0.2
- Internet Explorer 11.0.9600.18282
But these did display the same problem, of not producing more instances [but kept rewriting the file itself on the hard drive]
- Notepad2 4.2.25
- WordPad 6.1 Build 7601 (Service Pack 1)
And this one also had a problem, in that it spitted out a message that a file [that TXT with export results] could not be opened for writing [as apparently it took notice that it already was opened in it]
- Libre Office Writer 5.2.3.3
So this seems to be somewhat similar to this problem [F] Cannot drop files dragged from a Plain View selection from FreeCommander which has been recently taken care off by the Mp3tag developer [similar in that sense that some third party software had no problem with a specific cooperation with FreeCommander while Mp3tag unfortunately had]. So there is:
A] a question to @Florian: can this also be somehow adjusted, so that for example Notepad2 can open second inconstancy [with which in other circumstances Notepad2 has no problem whatsoever]?
B] a question to everybody else: do you also have the same problem after changing TXT handling software to those last 3 that I have listed?
If this cannot be dealt with in a similar way as that FreeCommander problem evoked by me, then it can be taken care off [most likely] by what I have postulated at the beginning: by creating the export file with a number at its end, each time an export action is ordered that number becoming bigger by 1. This second solution could be also beneficial for user that do not have this problem of mine, as it would allow to store the export result in form of individual files and not like as it is currently: with the most recent result in the file and the of the export results residing in the RAM
Come to think of it, instead of a number at the end, a better information would be a date followed by the hour [with the usage of seconds]. This way it would be more comprehensive. And then also the name of the action could be place after a mandatory EXPORT word in the beginning; thus creating something like ``EXPORT My export action for album titles 2018-06-22--21-05-59. Of course this expanded description could be implemented as an select-able option; with an additional option that would delete all of these export files when the Mp3tag is being closed