Illustrator not scaling proportionally

You are welcome, Sven.

The reason for my conclusion about random OP/computer errors is the comparison of widely different experience, corruption occurrance ranging from frequent to never, over a long range of exact same (upgrade/update) versions on different combinations of software and hardware of different qualities/levels of falliblity. You have been at the lucky end of the range, like I; I have never encountered it.

Sven,

I would certainly suggest your using the old preferences from Time Machine, which are obviously sound and give you back your preferred settings.

I believe yours is one of the confusing cases where multiple coincidences/strangenesses/corruptions gang up to mob an unsuspecting victim, in this case a (possibly temporary) general corruption distorting the logo scaling and interfering with the way Use Preview Bounds works and maybe the metric imprecision adding a final touch.

The interference suggestion is based on this:

The numbers involved in the downscaling from 50,3528 mm (where Use Preview Bounds adds the 1pt stroke to the 50 mm) to the attempted 10 mm which becomes 9,7143/9,4296 mm might suggest that the Use Preview Bounds is suspended/unused in the downscaled square, which would be consistent with your finding that things were precise when the Stroke was set inside because that would give the numbers corresponding to Use Preview Bounds being unticked (because there was no Stroke contribution to be added in the first place).

The the old preferences from Time Machine was obviously from before the corruption and therefore safe to use.

When a Preference corruption occurs, it happens when the preferences are (re)saved in connexion with closing down, and based on experience by many over some 15 years I am convinced it is always caused by some random saving error by the OS and/or computer components, maybe in combination.

However, there are also temporary corruptions that heal themselves when closing down. Therefore THE LIST shown below starts with a few easy steps to try first before the more (and more) meddling with the Preferences/installation further down the list (the full list goes further, into other aspects irrelevant here).

So it is conceivable that you just might have been able to get away with closing down/restarting (a number of times/a combination) as in 1) - 4) below, and then continue happily without replacing/resetting preferences.

Concerning the Use Preview Bounds: it certainly has its uses and can be crucial, but it can also cause confusion and errors when its effects are overlooked. I am careful to (remember to) switch it off when it has done its deed.

THE LIST

If things that should work simply refuse to (all possibilities exhausted including the A) - D) below (and carefully making sure you are performing (all) the needed things)), you may try (the relevant part(s) of) the list 1) - 8 ) below.

Sometimes, (certain) things may fail or stop working for no apparent reason. When the (other) possible reasons/cures fail to work, it may be some kind of (temporay or permanent) corruption, or even some inconvenient preference setting(s), which may be cured with something on the following list set up in an attempt to provide a catchall solution for otherwise unsolvable cases. It starts with a few easy and harmless suggestions 1) - 3) for milder cases, and goes on with three alternative ways 4) - 6) of resetting preferences to the defaults (easily but irreversibly and more laboriously but more thoroughly and also reversibly), then follows a list 7) of various other possibilities, and it ends with a full reinstallation 8 ). If no other suggestions work, or if no other suggestions appear, you may start on the list and decide how far to go and/or which may be relevant.

The following is a general list of things you may try when

A) The issue is not in a specific file,

B) You have a printer correctly installed, connected, and turned on if it is physical printer (you may use Adobe PDF/Acrobat Distiller as the default printer with no need to have a printer turned on, obviously you will need to specify when you actually need to print on paper), and

C) It is not caused by issues with opening a file from external media.

D) It is not caused by other applications (you may close down/disable everything else running, including browsers and antivirus, then try again). There are quite a few usual suspects that may disturb and confuse Illy (job description Adobe Illustrator) so she moves in mysterious ways (even more than usual, some would say).

You may have tried/done some of them already; 1) and 2) and 3) are the easy ones for temporary strangenesses, and 4) and 5) and 6) are specifically aimed at possibly corrupt/inconvenient preferences); 7) is a list in itself, and 8 ) is the last resort.

If possible/applicable, you should save current artwork first, of course.

1) Close down Illy and open again;

2) Restart the computer (you may do that up to at least 5 times);

3) Log out of your Adobe account and log back in;

4) Close down Illy, then close down al other applications, then open Illy again;

5a) Close down Illy and press Ctrl+Alt+Shift/Cmd+Option+Shift during startup (easy but irreversible);

5b) Or in the current CC version click Reset Preferences at the bottom right of the Preferences window and restart (also easy but irreversible);

6a) Move the folder (follow the link with that name) with Illy closed (more tedious but also more thorough and reversible), for CS3 - CC you may find the folder here:

https://helpx.adobe.com/illustrator/kb/preference-file-location-illustrator.html

https://community.adobe.com/t5/illustrator/moved-anchor-points-snap-back-to-original-location-after-releasing-in-illustrator-2020/m-p/10858481#M161820

6b) Or follow the instructions here: https://helpx.adobe.com/illustrator/using/setting-preferences.html

7) Look through and try out the relevant among the Other options (follow the link with that name, Item 7) is a list of usual suspects among other applications that may disturb and confuse Illy, Item 15) applies to CC, CS6, and maybe CS5);

Failing everything else, you may consider going on, but there are real dangers ahead unless you run one of the latest two CC versions, or unless you have the installers for both application(s) and possible update(s) on your computer, and even then you may need to restore plugins and whatnot afterwards if you have customized things:

8 ) A) Uninstall (ticking the box to delete the preferences if applicable), B) run the Cleaner Tool (if you have CS3/CS4/CS5/CS6/CC), and C) reinstall. You may try without step B), but sometimes it is needed, because otherwise things may linger.

As it appears from this thread, it may be worth repeating this if it fails to help the first time:

https://forums.adobe.com/thread/2283530

To uninstall:

https://www.adobe.com/search.html#q=uninstall%20illustrator&sort=relevancy&start=1

Cleaner Tool:

http://www.adobe.com/support/contact/cscleanertool.html

Thank you for following up, Sven.

I believe it makes no difference which you use; the keeping of the old one is mostly for cases where you wish to be able to fall back on certain contents/settings.

If you have non default settings, it may be worth keeping a sound version to fall back on, in case of corruption.

By the way, just as a curiosity, did the Use Preview Bounds return?

Sven,

Thank you for sharing. It is good to know that things work (better), although I am unsure whether that particular logo artwork can now be scaled in the right way.

Sometimes, replacing/resetting preferences can (also) give a relief by its changing an unwanted customized preference setting to thecorresponding default, such as your getting rid of the Use Preview Bounds (in the General Preferences) which gives you the 50,3528 mm (for a 1pt Stroke/outline).

I believe the wrong logo scaling shown may be caused by a corruption of the artwork/document. In some cases it is possible to rescue artwork (rather than your having to redo) by copying and pasting into a new document; and in those cases, replacing/resetting preferences will have no effect.

If you can rescue the artwork as described, you can try to switch back to the original preferences and see whether everything works the same way (with Use Preview Bounds (in the General Preferences) unticked).

It may be worth knowing that the latest version has a metric unit precision bug, as an unfortunate effect of going from three to four decimals yet to be weeded out, which may give you the funny and different decimals.

You can read on here, and join the request:

https://illustrator.uservoice.com/forums/601447-illustrator-bugs/suggestions/39906568-illustrator-24-1-metric-precision-broken

Sven,

How much are they varying, can you give some numbers before and after?