Hello, since the 4.15 When I pass the mouse over the preview boxes (mesh, material, etc) or In open a AnimBP the engine crash "D3D device being lost " Crash logs
Look at the ticket for a small list of workarounds that may help the issue.
If you want a quick and easy workaround that seemed to help a lot of people do the following.
Open the editor, open the Content Browser, select View Options (eye icon bottom right), and uncheck Real-Time Thumbnails. Source: here Thank You: IronicParadox
if you are using a laptop… do the following first.
connect your laptop to charger. open unreal engine and open file menu and hover mouse over it. if it works fine leave it. mostly the crash won’t happen.
disconnect your laptop from charger. now again… open unreal engine and open file menu and hover mouse over it. MOSTLY NOW… THE CRASH MAY OCCUR.
IF THE CRASH OCCURS… DO THE FOLLOWING.
NVIDIA GEFORCE EXPERIENCE → GAMES → BATTER BOOST → DISABLE IT !!!
AFTER DISABLING BATTERY BOOST ON NVIDIA GEFORCE EXPERIENCE… TRY THE ABOVE 2ND STEP AGAIN. NOW…IT SHOULD BE WORKING FINE MOSTLY.