════════ Exception caught by widgets library ═══════════════════════════════════
The following NoSuchMethodError was thrown building _BodyBuilder:
The method '+' was called on null.
Receiver: null
Tried calling: +("37")

The relevant error-causing widget was
Scaffold
lib/…/pages/pdf_page.dart:85
When the exception was thrown, this was the stack
#0      Object.noSuchMethod (dart:core-patch/object_patch.dart:51:5)
#1      MemoryPdf.getUserPath.<anonymous closure>  package:syncfusion_flutter_pdfviewer/…/common/pdf_provider.dart:109
#2      _IntListMixin.forEach (dart:typed_data-patch/typed_data_patch.dart:214:8)
#3      MemoryPdf.getUserPath package:syncfusion_flutter_pdfviewer/…/common/pdf_provider.dart:108
#4      SfPdfViewerState.didUpdateWidget package:syncfusion_flutter_pdfviewer/src/pdfviewer.dart:740
...
════════════════════════════════════════════════════════════════════════════════

════════ Exception caught by rendering library ═════════════════════════════════
Each child must be laid out exactly once.
The relevant error-causing widget was