How to reproduce:
1. Open the attached project
2. Open and Play Render Texture scene
3. Click on next video (>|) button twice
4. Click on play (>) button
Result: Notice that it glitches and spams this error
Assertion failed: Assertion failed on expression: 'srcAttach < m_CurrentFramebuffer.colorCount && "We should always resolve only current RT"'

NOTE: Issue occurs only on OpenGL and when texture (video_1_mat in this project) uses Anti Aliasing

Reproducible: 5.6.2f1 , 2017.1.0f2, 2017.2.0b1

Videos (reproducible):
Groot_H264_AAC_1280x720.mp4, 1280x720,H264 avc, Baseline@L3.1, 30, 2137 kb/s,AAC/LC,2,192 kb/s,44.1kHz
Groot_VP8_Vorbis_1280x720.webm,1280x720,VP8,30,1941 kb/s,Vorbis,2,112 kb/s,44.1kHz

Fixed: 2017.2.2p4 <- maybe in earlier version