Illustrator Beta 31.0.0.78 (Windows ARM64) – Large AI files fail to save with PDF compatibility enabled

Environment

• Application: Adobe Illustrator 2027 (Beta)

• Version: 31.0.0, Build 78

• Platform: Windows on ARM64

• Previous installed version: Build 64

• Updated to Build 78 on October 24, 2026

Problem

Adobe Illustrator Beta fails to save certain large and complex AI documents when "Create PDF Compatible File" is enabled.

The same document can be saved successfully when PDF compatibility is disabled.

The error message is:

"Illustrator cannot save the document due to unexpected errors."

No specific error code is provided.

Steps to reproduce

1. Open an existing large AI document containing approximately 3,137 editable text objects, numerous text-on-path objects, more than 50,000 vector paths, and two externally linked 16K TIFF images.

2. Select File → Save As.

3. Choose Adobe Illustrator (.ai).

4. Enable "Create PDF Compatible File".

5. Keep compression enabled and linked-file embedding disabled.

6. Attempt to save under a new filename.

Result: Illustrator reports an unexpected error and does not create the new file.

Repeat the procedure with "Create PDF Compatible File" disabled.

Result: The document saves successfully and can be reopened in Illustrator without warnings. Editable text and linked images remain accessible.

Additional observations

We performed several controlled tests:

Test 1 – Small Illustrator document

• PDF compatibility enabled

• Save and reopen successful

Test 2 – Large English cartographic document

• Original file size: approximately 710 MB

• PDF compatibility enabled

• Save failed

Test 3 – Same document

• PDF compatibility disabled

• Save successful

• Resulting file approximately 533 MB

• Native reopening successful

Test 4 – Large German cartographic document

• Approximately 1.2 GB

• PDF compatibility enabled

• Successfully saved and reopened with Build 78

This suggests that the problem is not simply caused by file size or a general inability of Build 78 to save PDF-compatible documents.

The documents contain complex editable cartographic vector data, including detailed coastlines, geographic labels, text paths and externally linked high-resolution TIFF images.

Version history

We confirmed through Adobe installation logs that Illustrator Beta was updated from Build 64 to Build 78 on October 24, 2026.

A German cartographic document was successfully saved with Build 64 on October 22.

However, another large PDF-compatible document was also successfully saved with Build 78.

Therefore, we cannot confirm that the update introduced the problem.

Separate issue observed

During another controlled test, embedding very large 37K TIFF resources resulted in an AI document whose PDF representation remained intact, while Illustrator reconstructed only part of its native object structure after reopening.

The native data still appeared to be present in the file.

We have not established whether this issue is related to the PDF-compatible saving failure described above.

Expected behavior

Illustrator should save large and complex documents with PDF compatibility enabled while preserving the complete editable native object structure.

If a document cannot be saved, the application should provide a meaningful error message identifying the cause.

Questions for the Illustrator Beta team

1. Is there a known issue with PDF-compatible saving of large, complex AI documents in Illustrator Beta 31.0.0.78 on Windows ARM64?

2. Are there known limitations involving large numbers of vector paths, text-on-path objects or linked TIFF resources?

3. Is there a recommended workaround that preserves PDF compatibility?

4. Would diagnostic logs or a reduced reproduction file help investigate this issue?

We can provide screenshots, version information and additional diagnostic details.

The original production files have been preserved unchanged.