A series has invalid periods
Cf https://sentry.io/organizations/dbnomics/issues/3065509812/?project=5548941&query=is%3Aunresolved
The series UNDATA/NASEC_IDCNFSA_A/A.N.AM.W0.S14.S1.N.D.P51G._Z._Z._Z.XDC._Z.S.V.N._T
periods are empty strings.
Cf https://sentry.io/organizations/dbnomics/issues/3065509812/?project=5548941&query=is%3Aunresolved
The series UNDATA/NASEC_IDCNFSA_A/A.N.AM.W0.S14.S1.N.D.P51G._Z._Z._Z.XDC._Z.S.V.N._T
periods are empty strings.