TortoiseGit dialogs may not be visible (when a modal sub dialog is shown too early during initialization)
Win10x64, just updated to 2.17 from 2.16 and...
I had to immediately resolve merge conflict and push the changes. Actually i even did, i just had to commit the results. Yiou would say, not the time to upgrade soft, but i used to think Tortoise was very reliable :-)
So, after i upgraded - the TGit settings windows were visible, but TGit commit were never! I did few reboots, did not helpt. I use DWMBlurGlass so i thought it was a confllict, deinstalled it - still nothing.
I run Windows Detective - and all the windows of TGit saw normal, their rects "flashed" where they should, except they never rendered, like it either having 100% transparency or having WM_PAINT events totally broken. I could not close the windows using the Detective, could not change windows attributes, felt like the TGit windows no longer received Windows Messages... Actually, i think i saw such errors from Windows Detective once. Granted WD is pretty obsolete program and probably misses a lot of most current HWND features, but the "old school" properties did not look abnormal to me.
The TGit settings window was ok, but never the commit one.
Panicing, i downloaded what i was thinking was the prior stable, actually it was the 2.16.2 preview. It did not work either. In the end i figured out i have to abandon the download page and dive into folders tree, there i downloaded 2.16.0 and reinstalled and it worked like a charm again.
NOTICE: i believe your download site rather offered TWO stable versions, current and prior, IMMEDIATELY on the download page. Because "latest preview" has huge chances to be just a renamed current stable and has the same blockers. Basically, if the user hits the wall after yupgrade he would need to quickly revert to prior STABLE version and your site does not help him, perhaps even misleads him.
It seems to me you injected an intermediate DirectX or something layer in that small "alert" windows on top of the commit window, they made this "this is not your usual commit, this is a special merge-conflict commit!" notice. I speculate that experiment went awry. But i am not sure. At least i repeat the settings dialog which had no such an alert disabling it was rendered fine.
However i think you'd rather somehow prepare for more unlucky win10 users getting totally blocked and maybe give them easy way to reverting to 2.16.0 before they flooded the forums...
Oh, and one more crazy thing, the taskbar "peep" effect worked like the charm, i could hover the taskbar button and then see the "intended image" of the TGit, but would i switch to it - an nothing was ever seen. WinDet's "drag the picker to any window" feature also could not see the TGit's dialogs.
Alt+Tab and Alt+Esc AFAIR did not see the broken windows too, Alt+Space did not open move/resize menu, nothing short of killing from the task manager the whole tgit procedure process could anyhow affect those ghost windows.