Steps:
1. Add GameObject to the Hierarchy
2. Drag it to Project Browser to make a prefab out of it
3. Drag it again to Project Browser and choose "Prefab Variant"
4. Select both assets and delete them
==>
Prefab instance in Hierarchy becomes red
5. Drag Prefab instance to the Project Browser again
6. Right-click on the prefab asset and choose "Reimport"
==>
Assertion failed on expression: 'm_hasValue'
Assertion failed on expression: 'type != SubFilterType::Exact'
Assertion failed on expression: '!subFilter.dbPath.empty() || subFilter.type != SubFilterType::Exact'
Assertion failed on expression: 'itGuid != guidMap.end()'
Assertion failed on expression: 'metaFileHash.IsValid()'

Please, take a look into movie for details (+ a small debugging)

Not repro in
Version 2019.3.0b7 (82807b239940)