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AP_122021873-Newcomer
3-Newcomer
Oct 13, 2026 4:35 PM UTC
Solved

Mathcad Prime 12 freezes after changing result units

I am using PTC Mathcad Prime 12.0.0.0 (Academic). Whenever I change a result’s displayed unit, the calculation region turns grey and dependent expressions stop evaluating. Automatic calculation is enabled, but the AUTO indicator remains orange.

Simple example:

  1. Define d := 3 mm

  2. Define a := d³ · π and evaluate it.

  3. Change the result unit from L to mm³.

  4. The result displays approximately 84.823 mm³, but the region stays grey and a subsequent evaluation of a shows “?”.

Recalculating the worksheet does not resolve the issue.

terryhendicott
terryhendicottAnswer
21-Topaz II
Oct 29, 2026 5:30 AM UTC

Hi,

You say “Define a := d³ · π and evaluate it.”

What do you mean by evaluate it?  Go to Calculation Tab, Controls section and make sure Auto Calculation is selected.  This calculates the sheet as you make changes.

Cheers

Terry

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3 replies

LucMeekes23-Emerald V
23-Emerald V
Oct 14, 2026 6:47 AM UTC

In my Prime Express there's no problem:

Select the (grey) region and, in the menu, under the ‘Calculation’ ribbon, check if ‘Disable calculation’ is active.

Consider update to Prime 12.0.0.1.

 

Success!
Luc

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JeffH1
JeffH116-Pearl
16-Pearl
Oct 28, 2026 10:26 PM UTC

Machine issue?  Out of memory?  Is there anything else running on the machine?  Can you open and run other programs successfully after this occurs?  I’m assuming it is repeatable on your machine?

No problem on Express and no problem on licensed Mathcad Prime.

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terryhendicott
terryhendicott21-Topaz IIAnswer
21-Topaz II
Oct 29, 2026 5:30 AM UTC

Hi,

You say “Define a := d³ · π and evaluate it.”

What do you mean by evaluate it?  Go to Calculation Tab, Controls section and make sure Auto Calculation is selected.  This calculates the sheet as you make changes.

Cheers

Terry

Translate
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