An addon-native error (not a LUA error but the actual built-in exception handler for Applicant Filter) is triggered for every applicant in the list that does not have RIO progress for the raid to which they are applying.

For example, consider there are five applicants:

• Applicant 1 has Raider.io progress of 'Nerub'ar Palace Normal 8/8' and 'Nerub'ar Palace Heroic 1/8' (i.e. 8/8 N and 1/8 H)
• Applicant 2 has no Raider.io progress of any kind (i.e. just a fresh max-level character with no prior raid experience)
• Applicant 3 has no Raider.io progress of any kind ("")
• Applicant 4 has 5/8H and nothing registered for Normal (i.e. tooltip for RIO just shows 5/8 H for the raid to which they are applying)
• Applicant 5 has prior raid experience in their tooltip - just not for the current raid to which they are applying (e.g., 8/8 Awakened XYZ)

Addon-native error suggesting "syntax is right but there are no matches" (along those lines) is triggered, repeatedly, for applicant 2 and applicant 3. The error(s) are resurfaced for every new applicant that enters the queue.

Could you please provide the filter expression you are using and also a screenshot? Variable rionormalprogress (and similar) should be 0 for a character without any rio progress. In fact, those variables should be even zero if you do not have rio addon installed.