SAFE_POINT on creating object relation in Dbi

Scenario 1
1. Open an alignment
2. Build the tree
3. Unload both documents (alignment and tree)
4. Load alignment
Current state: SAFE_POINT is triggered

Unexpected query result code: 19 (foreign key constraint failed)
Trying to recover from error: Unexpected query result code: 19 (foreign key constraint failed) at src/models/GObject.cpp:195

Scenario 2:
1. Open "human_T1.fa"
2. Open "GFF/5prime_utr_intron_A21.gff"
3. Drag and drop "Ca21 chr5 features" to "human_T1"
4. Unload both documents
5. Load "human_T1.fa" document
6. Load "GFF/5prime_utr_intron_A21.gff" document
Current state: the same SAFE_POINT is triggered