Importing a PDF via "picture" button erases/ corrupts whole note - all content lost

[Isolator70]

Describe the bug

Using the "Picture" (German: "Foto") button to import a PDF (only a picture stored inside the PDF). It is possible to select the PDF but it is not shown in the note.
After that step one can see, that all previous content of the note is invisible, also PDF is not visible!
Leaving the note one can see the former content of the note in preview mode, but by opening it an errormesage is greeting the user "...write protected..." and ALL content is LOST (I lost two days note of a seminar (17 pages)...sad.)

To reproduce

1. Create an new note
2. Enter something with the pencil
3. Click the "Picture" button in the tool bar
4. select a PDF file
5. Check if the PDF and the former handwritten content is still present
6. Result: Nothing visible anymore
7. Leave note
8. Check preview of note: Handwritten content visible in preview
9. Open note: Errormessage greets the user
10. Result: All content is lost.

Occurence: 100% Systematically

Looking into logfiles one can see some entries (screenshot):

Logfile content itself:

SEVERE at [2026-02-20 13](tel:2026-02-20 13):37:30.943144
Exception: Invalid image data
#0 _futurize (dart:ui/painting.dart:8570)
#1 ImageDescriptor.encoded (dart:ui/painting.dart:8351)
#2 PngEditorImage.firstLoad. (package:saber/components/canvas/image/png_editor_image.dart:141)

#3 PngEditorImage.firstLoad. (package:saber/components/canvas/image/png_editor_image.dart:143)

#4 PngEditorImage.firstLoad (package:saber/components/canvas/image/png_editor_image.dart:140)

SEVERE at [2026-02-20 13](tel:2026-02-20 13):37:30.945209
Exception: Invalid image data
Exception: Invalid image data
#0 _futurize (dart:ui/painting.dart:8570)
#1 ImageDescriptor.encoded (dart:ui/painting.dart:8351)
#2 instantiateImageCodecWithSize (dart:ui/painting.dart:2575)
#3 PaintingBinding.instantiateImageCodecWithSize (package:flutter/src/painting/binding.dart:147)
#4 MemoryImage._loadAsync (package:flutter/src/painting/image_provider.dart:1719)

#5 MultiFrameImageStreamCompleter._handleCodecReady (package:flutter/src/painting/image_stream.dart:1021)

SEVERE at [2026-02-20 13](tel:2026-02-20 13):37:48.309070
Failed to load file: type 'Null' is not a subtype of type 'int'
type 'Null' is not a subtype of type 'int'

SEVERE at [2026-02-20 13](tel:2026-02-20 13):41:26.835383
Failed to load file: type 'Null' is not a subtype of type 'int'
type 'Null' is not a subtype of type 'int'

SEVERE at [2026-02-20 13](tel:2026-02-20 13):41:46.637333
Failed to load file: type 'Null' is not a subtype of type 'int'
type 'Null' is not a subtype of type 'int'

SEVERE at [2026-02-20 13](tel:2026-02-20 13):41:55.258863
Failed to load file: type 'Null' is not a subtype of type 'int'
type 'Null' is not a subtype of type 'int'

Expected behavior

1. The PDF becomes visible in Sabre without erasing any previous content.
2. If the PDF cannot be imported that way (if it is intended for pictures only) a meaningful hint should be shown to the user how to do it right.

Saber version

1.31.1, F-Droid

Device

• Device: Samsung Galaxy Tab S6 Lite (SM-P615)
• OS: LineageOS 23.0

Anything else?

Maybe something like "snapshots" of notes to go back to an previous version (-10 minutes, -1h, -12h, -ndays) would be great as also user itself could do mistakes.

Before submitting an issue, please check the following

• I have searched for similar issues (both open and closed) and cannot find a duplicate
• This is not an automated submission and has been written by a human.

[gutierrezmgabriel-design]

I don't think this is an issue stemming from how you are uploading your pdfs. I upload them via the "import note" button that appears when you click "+" on the homepage, and this issue has been plaguing me too. After I exit a pdf note, if I re-open the file, nothing is visible. I've lost weeks of notes :((

[QubaB]

If you are synchronizing notes to Nextcloud, then try to look at details and file versions in web browser. There can be some files in the history. However it can be difficult to find correct file because file names are encrypted.

It is my guess I never tried this way to restore note.