extendscript alert truncates message in unexplained ways

alert("abcdefghijklmnopqrstuvwxyz"); in a script only shows abcdefghijklmnopqrstuvwx in the message box in After Effects on Windows.

I know there are alternatives, but for one-off scripts or quick debugging an alert can really help. However, the message displayed by alert truncates things in very hard to explain or predict ways. I’ve taken to adding a bunch of junk at the end of the message (like some words and line breaks in an attempt to figure out what causes this issue) in order for it to work, but then it displays some of or all of the junk too.

I’ve tried to determine if there was some pattern with length of substrings, numbers vs letters vs characters vs whitespace, line breaks, etc but no luck

Steps to reproduce:

create a .jsx script file with the following contents:

alert("abcdefghijklmnopqrstuvwxyz"); // abcdefghijklmnopqrstuvwx

alert("1234567890klmnopqrstuvwxyz"); // 1234567890klmnopqrstuvwxy

alert("c:\\test\\a\\path\\to\\project.aep"); // c:\test\a\path\to\project.a

alert("aaabbbcccdddeeefffggghhhiiijjjkkklllmmmnnn ooopppqqqrrrssstttuuuvvvwwwxxxyyyzzz"); // aaabbbcccdddeeefffggghhhiiijjjkkklllmmmnnn

alert("aaabbbcccdddeeefffggghhhiiijjjkkklllmmmnnn"); // aaabbbcccdddeeefffggghhhiiijjjkkklllmmm

go to File->Scripts->Run script file.. and choose this script

It does not need to be this exact script file, these are just some examples that show things displaying weird. Initially I noticed this by showing a message box with a file path, which is something that consistently seems to be a problem.

Expected result:

the exact string in the alert call shows up in a message box

Actual result:

The message box that appears truncates the text in strange ways (as noted by the comments)

Adobe After Effects version: Beta 27.0.0 Build 42 -- works properly in non-beta release version 26.3.0 Build 87. Oddly enough I noticed this in Beta 25 and 26 versions, too, but didn't bother to report at the time.

Operating System: Windows 11 24H2 26100.8875