Custom info constants are truncated after the '/' character when saving and reopening .PZF/.PZFX files on Mac Prism

The issue

If an Info sheet constant contains a forward slash (for example 123/567 or Sample/Control), Prism 11.1.0 and earlier truncate everything after the slash when the project is saved in the legacy .pzf or .pzfx format and then reopened. 123/567 becomes 123.

No warning or error appears. The value simply looks shorter than it should, so the problem often goes unnoticed until a linked graph, layout, or table displays incomplete text.

Affected versions: Prism 10.0.3, 10.6.1, and all Prism 11 versions through 11.1.0.

Affected formats: Legacy .pzf and .pzfx only. The current .prism format is not affected in any version.

How to fix the issue

Update to Prism version 11.2.0 (build 301 or newer). Once available, update directly via Help > Check for updates in Prism or download the latest version from the GraphPad Updates page.

What to do after updating to Prism 11.2

What you need to do depends on which legacy format your files are saved in. The two cases are different, and only one requires manual work.

Files saved as .pzf: no action needed

The complete constant was always written to the file. Only the reading step was broken. Open the file in Prism 11.2 and the full value appears, including anything after the slash. Nothing is lost and nothing needs re-entering.

We recommend resaving these projects in the .prism format while you have them open.

Files saved as .pzfx: manual review and re-entry required

Older versions discarded the text after the slash before writing the file, so it was never stored on disk. Prism 11.2 cannot recover data that is not in the file.

For each affected project:

1. Open the file in Prism 11.2.
2. Go to the Info sheet and check every constant that should contain a slash.
3. Re-enter the missing text by hand, using your original records as the source.
4. Save the file in the .prism format.

Important: do not reopen and resave affected files in an older version

Saving a file in Prism 11.1.0 or earlier reapplies the truncation. This matters in two ways:

• For a .pzfx file you have just repaired, the text you re-entered is lost again.
• For a .pzf file, the intact value stored on disk is overwritten with the truncated one, turning a fully recoverable file into permanent data loss.

If you share projects with colleagues, make sure everyone who opens these files has updated to 11.2 before anyone saves. Saving in the .prism format removes this risk entirely.

How to spot a truncated constant

Because truncation is silent, a shortened value looks like a legitimate one. When reviewing older .pzfx files, check:

• Constants that end abruptly or read as incomplete
• Any constant that should follow a known pattern, such as an ID, a ratio, a date, or a concentration
• Text on graphs, layouts, and tables that is populated by Info sheet links

Why does this issue occur?

In legacy .PZF and .PZFX file architectures, the parsing and serialization routine for custom Info sheet constants incorrectly treated the forward slash (/) symbol as an internal delimiter/separator rather than literal text.

• In .pzfx (XML-based) files saved with older versions, the data after the slash was stripped during file generation, leaving the truncated string permanently written to the file.

• In .pzf files, the full data was recorded, but older Prism versions failed to parse past the slash character upon opening.

This is why .pzf files can be recovered by updating and .pzfx files cannot.

What are the workarounds?

If you are working on an affected version of Prism or collaborating with team members who use older versions:

1. Use the modern .prism file format: Save your projects using the standard .prism format instead of .pzf or .pzfx. The .prism format handles all characters (including /) correctly across all Prism 10 and 11 versions.

2. Avoid using / in custom info constants: If you must save your work in a legacy .pzf or .pzfx format, replace the forward slash (/) with alternative separators such as dashes (-), underscores (_), colons (:), or spaces (e.g., "123-567" instead of "123/567").