diff --git a/core/classifiers/create.js b/core/classifiers/create.js
index 56de92663..e721b74a2 100644
--- a/core/classifiers/create.js
+++ b/core/classifiers/create.js
@@ -62,7 +62,12 @@ module.exports = async (req, res) => {
 
     // Get the classification ids for each output (or error if not found)
     const outputMappings = params.classificationValues.map(parseClassifierOutputMapping)
-    const serverIds = await getIds(outputMappings.map(value => value.to))
+    let serverIds = {}
+    try {
+      serverIds = await getIds(outputMappings.map(value => value.to))
+    } catch (_) {
+      throw new ValidationError(_.message)
+    }
     const outputs = outputMappings.map(value => ({ className: value.from, id: serverIds[value.to] }))
 
     const createdById = req.rfcx.auth_token_info.id