(EDIT: Kinda solved!) Sound gone and Add-Ons not loaded

[Hammerfritz]

Greetings, fellow Wesnothians!

So I've been encountering the same error during the past few days repeatedly, but never before: After editing one of my scenarios, I try to test it, but Wesnoth (1.12.6 in German, on Windows 10) does not load add-ons (sometimes with one specific add-on being loaded while others aren't, but not always). This behaviour goes along with missing sounds in the interface, but no error report is provided. Initially I thought this was caused by corrupt wml, but manually reinstating previous states of the edited file does not solve the problem, while just waiting for a few hours without making any changes and then trying again seems to work. What does not help either is reinstalling Wesnoth or restarting the computer. I'm quite convinced that editing the add-on is the trigger, but I cannot tell for sure since I haven't done much else in Wesnoth recently. I shall update this post if I find anything new.
EDIT: Still seems to be the only trigger but found "20170323 16:04:30 error filesystem: Trying to open file with empty name." in stderr.txt

[nuorc]

Did you check stderr and the Windows event viewer? Maybe that'll help hunt the culprit down.

[Hammerfritz]

Thank you!
I did not expect to find anything, as no error report was displayed in-game. Seems like I'm a dork. stderr says:
"20170323 16:04:30 error filesystem: Trying to open file with empty name."

Anyway, I checked for any such file in the places I might have edited the past few days while the game was still running, unlucky so far.

[nuorc]

It's totally speculative, but I thought maybe windows (a virus checker, another app...) was 'holding' a file which BfW could only access later.

Are you compressing your scenarios? I believe that's not necessary, but in case you do maybe give it a wild shot and try without.

[Hammerfritz]

It's totally speculative, but I thought maybe windows (a virus checker, another app...) was 'holding' a file which BfW could only access later.

Are you compressing your scenarios? I believe that's not necessary, but in case you do maybe give it a wild shot and try without.

Like the ideas, but it doesn't seem to be the case. I think I can avoid the problem to be triggered if I not just save the file but also close the editor - probably a stupid habit not to do so anyways. Doesn't explain why that never happened before, and still happens sometimes, but I'm on some kind of track now. Thank you again for your kind advice!