Compatibility Report

• Name of the game with compatibility issues: Microsoft Flight Simulator X: Steam Edition
• Steam AppID of the game: 314160

System Information

• GPU: Nvidia GTX 1070
• Video driver version: nvidia 580.159.03
• Kernel version: 6.8.0-124-generic
• Link to full system information report as Gist: https://gist.github.com/rakslice/4353a68acb0e3169cffd4d50680a5eb4
• Proton version: 10.0-4

I confirm:

• [ x] that I haven't found an existing compatibility report for this game.
• [ x] that I have checked whether there are updates for my system available.

Proton log of this repro: steam-314160.log

Symptoms

In multi-line text areas displaying canned text in dialogs, the first line of the text is repeated over and over instead of displaying the correct text.

This occurs in, for instance, the "Aircraft Details" screen (change aircraft in the launcher or Aircraft -> Change Aircraft, details), and the "Facility Information" screen (World -> Map, click on an airport), which is important in game for getting ILS radio details from.

Reproduction

1. Set Launch Options WINEDLLOVERRIDES="d3d10=n;d3d10_1=n" %command% to get the game to launch properly (it appears to be using dxvk but 3d matters are not relevant to this issue)
2. Launch the game. After the splash screen the launcher appears.
3. A certificate error appears on the news page loading; just say no.
4. Go to "Free Flight" from the left side navigation bar.
5. Click the "Change" button under "Current Aircraft"
6. Click the "Details" button at the bottom to see the details of whatever aircraft is selected. The Aircraft Details screen appears.

Expected:

A multi-line aircraft description is shown properly in the bottom left text area

Actual:

The bottom left area just shows a single line of text repeated

More info

This bug is a general problem with various pre-2020 Flight Simulator versions (X, 2004, 2002, 2000, etc.) in wine.
There is a wine bug report at https://bugs.winehq.org/show_bug.cgi?id=43493 that appears to be about this precise behaviour, where a commenter has a detailed technical explanation and proposed fix:

It appears to be caused by some buggy code which supports a custom MFC control in C:\Program Files\Microsoft Games\FS2000\IMGUI.DLL. When this custom control is created, it passes its WM_NCCREATE message on to the edit box. This causes the edit box to reinitialise and, in so doing, the ES_MULTILINE style is lost. Later, EM_GETLINE is sent to the Edit control and, because it is not a multi-line control, it returns all the text every time it is called.

So this is a bug in MS Flight Simulator. Presumably Windows ignores repeat WM_NCCREATE messages to an Edit control, which is why the bug is not apparent on Windows.

The problem can be resolved in Wine by patching the user32.dll in the edit.c file as follows:

At the start of the EDIT_WM_NCCreate() function, add the following line:

if ((EDITSTATE*)GetWindowLongPtrW(hwnd, 0)) return TRUE;

This attempts to retrieve the existing EDITSTATE if the Edit control already exists. If successful, the function returns, effectively ignoring the WM_NCCREATE message.

I can't practically rebuild proton or get a debugger breakpoint in the right place to test this early return with my steam copy of proton, so I don't know if this explanation is correct or the proposed fix works or not.

General notes for running the game, once past the launcher in the actual game (not necessary for this repro):

• Once past the launcher, the game's full screen mode doesn't work and is the default. Use Alt-Enter to switch out of the full screen mode to windowed mode; if the full screen mode actually hangs the process, rerun with launch option PROTON_USE_WINED3D=1 temporarily, switch to windowed mode, and exit the game normally; the windowed mode will then be used by default in subsequent runs.
• Use protontricks to install corefonts to fix missing menus and other text in the actual game window