How to reproduce:
1. Open 'SampleScene' from attached project
2. Start Play mode
3. In Game window click "Load Broken"
4. Inspect Console

Expected result: Only "Loaded: 61 assets" message appears
Actual result: 'Loaded' message may or may not appear, multiple warning pairs get thrown either a few times or continuously:
"Internal: JobTempAlloc has allocations that are more than 4 frames old - this is not allowed and likely a leak"
"To Debug, enable the define: TLA_DEBUG_STACK_LEAK in ThreadsafeLinearAllocator.cpp. This will output the callstacks of the leaked allocations"

Reproducible with: 2018.4.16f1, 2018.4.17f1
Not reproducible with: 2017.4.36f1, 2018.4.15f1, 2019.2.20f1, 2019.3.0f6, 2020.1.0a22

Workaround: Access assets directly like "AssetBundleRequest.allAssets" before calling yield

Notes:
1) Some interactions with Editor might stop the loading loop and cause it to finish.
2) Bundle with fewer textures(3 while original is 61) does not produce warnings but still fails to load.