Invalid analyzers are refused when the index is created
What changes in Invalid analyzers are refused when the index is created compared with MongoDB and what your application has to do.
This difference is of the Stronger guarantee kind.
What MongoDB does
mongot accepts the definition and leaves the index in the FAILED state.
What TeselaDB does
An analyzer with minGram 0 or with a regex replacement that names a missing group is refused when the index is created.
What your application has to do
Fix the analyzer definition; the error says which part fails.