Name: Firefox Version: 46.0a1 Build ID: 20160121030208 Update Channel: nightly User Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:46.0) Gecko/20100101 Firefox/46.0 The profile manager window empty until a repaint is triggered by e.g. moving the mouse over the positions of the button. So this might be a hardware acceleration issue. Same issue occurs when the dialog to create a new profile gets opened. Steps to reproduce: 1. From a command console, launch: firefox.exe -no-remote -P Graphics -------- Adapter Description: Intel(R) HD Graphics 4600 Adapter Description (GPU #2): NVIDIA GeForce GTX 765M Adapter Drivers: igdumdim64 igd10iumd64 igd10iumd64 igdumdim32 igd10iumd32 igd10iumd32 Adapter Drivers (GPU #2): nvd3dumx,nvwgf2umx,nvwgf2umx nvd3dum,nvwgf2um,nvwgf2um Adapter RAM: Unknown Adapter RAM (GPU #2): 2048 Asynchronous Pan/Zoom: wheel input enabled Device ID: 0x0416 Device ID (GPU #2): 0x11e2 Direct2D Enabled: true DirectWrite Enabled: true (6.3.9600.18123) Driver Date: 11-20-2015 Driver Date (GPU #2): 12-16-2015 Driver Version: 10.18.14.4332 Driver Version (GPU #2): 10.18.13.6143 GPU #2 Active: false GPU Accelerated Windows: 1/1 Direct3D 11 (OMTC) Subsys ID: 35371558 Subsys ID (GPU #2): 35371558 Supports Hardware H264 Decoding: Yes Vendor ID: 0x8086 Vendor ID (GPU #2): 0x10de WebGL Renderer: Google Inc. -- ANGLE (Intel(R) HD Graphics 4600 Direct3D11 vs_5_0 ps_5_0) windowLayerManagerRemote: true AzureCanvasBackend: direct2d 1.1 AzureContentBackend: direct2d 1.1 AzureFallbackCanvasBackend: cairo AzureSkiaAccelerated: 0 Nvidia driver version is 361.43.

Encountered the same behavior with latest Nightly 46.0a1 (from 2016-01-21), under Windows 7 64-bit, Windows 10 64-bit and Windows 10 32-bit. Not reproducible with Mac OS X 10.10.5 nor Ubuntu 14.04 32-bit.

This was fixed by backed out Bug 1239861.