see also #331

src/components/Widgets/Test/TestParticipation/TestParticipation.vue

@@ -160,7 +160,7 @@ export default {
     },
     onSingleQuestionsSentSuccess () {
       this.answerBook.loading = false
-      this.backToClassList()
+      // this.backToClassList()
     },
     onSingleQuestionsSentFailed () {
       this.answerBook.loading = false

src/components/Widgets/Test/TestParticipation/components/AllQuestions.vue

@@ -75,12 +75,12 @@ export default {
     },
     isFileSizeGtThan (targetSize) {
       const file = FormBuilderAssist.getInputsByName(this.inputs, 'answer_attachment').value
-      const fileSizeinMb = file.size ? file.size / 1000000 : 0
+      const fileSizeinMb = file?.size ? file.size / 1000000 : 0
       return fileSizeinMb > targetSize
     },
     isPdfFile () {
       const file = FormBuilderAssist.getInputsByName(this.inputs, 'answer_attachment').value
-      return file.type ? file.type === 'application/pdf' : true
+      return file?.type ? file.type === 'application/pdf' : true
     },
     sendAnswers () {
       if (this.isFileSizeGtThan(10)) {

src/components/Widgets/Test/TestParticipation/components/SingleQuestion.vue

@@ -135,12 +135,12 @@ export default {
     },
     isFileSizeGtThan (targetSize) {
       const file = FormBuilderAssist.getInputsByName(this.inputs, 'answer_attachment').value
-      const fileSizeinMb = file.size ? file.size / 1000000 : 0
+      const fileSizeinMb = file?.size ? file.size / 1000000 : 0
       return fileSizeinMb > targetSize
     },
     isImageFile () {
       const file = FormBuilderAssist.getInputsByName(this.inputs, 'answer_attachment').value
-      const fileType = file.type ? file.type : 'image/'
+      const fileType = file?.type ? file.type : 'image/'
       return fileType.startsWith('image/')
     },
     sendAnswer () {