Create more than five overlapping stationary lights in the scene and switch the scene visualization mode from Shaded to Shadowmask Overlap. The console log prints Invalid memory pointer was detected in ThreadsafeLinearAllocator::Deallocate! and TLS Allocator ALLOC_TEMP_THREAD, underlying allocator ALLOC_TEMP_THREAD has unfreed allocations errors.

Steps for reproduction:
1) Create an empty scene with five overlapping stationary lights or download the project below
2) Switch the scene visualization mode from Shaded to Shadowmask Overlap
3) Observe the bug in console log

Notes:
- Works as expected in 5.6.0b4 (rev. f8c731df0021)
- Regression introduced in 5.6.0b5 (rev. 721ff8e6f757) and it also occurs in 5.6.0b6 (rev 7bd0afcf3c9c)