Appears to be a known issue which is currently being reviewed: "Error: Picklist value does not exist" in Search Filter Fields for Record Type values with commas
N.B. It might be important to point out that an error may not always be thrown for this issue. Appears record types containing commas are actually being split into separate filters. Eg. a record type filter of "One, Two" is being split into "One" and "Two" at which point the filter is applied. So if you have a record type of "Two", then results will be returned for that. If you have both "One" and "Two" as record types, you will get those results back, but never "One, Two" results. An error is only thrown if neither "One" nor "Two" are valid record types. Hope that makes sense.
When the Record Type field is used as a Search Filter Field and record type name contains a comma, selecting record type value with commas from the search filter picklist, throws error "Error: Picklist value does not exist"
- Create a Record Type with label containing comma ','
- Add Record Type as search filter field for the object where you have created the record type in step 1.
- On search result page click on Show Filters and select the record type you have created with comma under the Record Type filter picklist.
- Click Apply Filters
Error: "Error: Picklist value does not exist"
Remove comma from the record type label or user other characters like hyphen.