diff --git a/src/file/generateFileUploadForm.ts b/src/file/generateFileUploadForm.ts
index 5e2cdcc..e358c08 100644
--- a/src/file/generateFileUploadForm.ts
+++ b/src/file/generateFileUploadForm.ts
@@ -5,8 +5,11 @@ export const generateFileUploadForm = (
   data: any
 ): FormData => {
   for (const tableName in data) {
+    if (!Array.isArray(data[tableName])) continue
+
     const name = tableName
     const csv = convertToCSV(data[tableName])
+
     if (csv === 'ERROR: LARGE STRING LENGTH') {
       throw new Error(
         'The max length of a string value in SASjs is 32765 characters.'
diff --git a/src/utils/convertToCsv.ts b/src/utils/convertToCsv.ts
index 9cc5565..8ff5f97 100644
--- a/src/utils/convertToCsv.ts
+++ b/src/utils/convertToCsv.ts
@@ -3,7 +3,7 @@
  * @param data - the array of JSON objects to convert.
  */
 export const convertToCSV = (
-  data: any,
+  data: Array<any>,
   sasFormats?: { formats: { [key: string]: string } }
 ) => {
   let formats = sasFormats?.formats
@@ -76,7 +76,7 @@ export const convertToCSV = (
               return byteSize
             }
           })
-          .sort((a: number, b: number) => b - a)[0]
+          .sort((a: any, b: any) => b - a)[0]
 
         if (longestValueForField && longestValueForField > 32765) {
           invalidString = true