Here is the exact error, but note that it doesn't matter what the name of the hierarchy is,

Error: Prolog procedure line (12):  DIMENSIONHIERARCHYCREATE: Cannot create hierarchy "Lifestage": dimension "Item" already has element names/aliases containing metacharacters.

I'm assuming this is saying that there are reserved characters already in use somewhere? Has anyone come across this?

------------------------------
John O'Leary
------------------------------

Hi John,

Internally TM1 uses tab characters to separate hierarchy and element names in some cases. That tab character, AFAIK, is still the only 'metacharacter'. TM1 doesn't complain if you don't have alternate hierarchies, because it can't get confused until you do, but if you want to take advantage of alternate hierarchies you can no longer have tab characters in your element names or aliases, and that's what this error is trying to tell you.

------------------------------
Hubert Heijkers
STSM, Program Director TM1 Functional Database Technology and OData Evangelist
------------------------------

Thanks Hubert, much appreciated. I'll go searching for this.

------------------------------
John O'Leary
------------------------------

Original Message:
Sent: Mon November 03, 2025 03:24 AM
From: Hubert Heijkers
Subject: Error when attempting to create a hierarchy

Hi John,

Internally TM1 uses tab characters to separate hierarchy and element names in some cases. That tab character, AFAIK, is still the only 'metacharacter'. TM1 doesn't complain if you don't have alternate hierarchies, because it can't get confused until you do, but if you want to take advantage of alternate hierarchies you can no longer have tab characters in your element names or aliases, and that's what this error is trying to tell you.

------------------------------
Hubert Heijkers
STSM, Program Director TM1 Functional Database Technology and OData Evangelist
------------------------------

Confirming that the issue was the use of a Tab character in 2 Element names. 

Perhaps an enhancement to the error message might help. Perhaps an extension to say that the tab character may be the issue.

Thanks again

------------------------------
John O'Leary
------------------------------

Original Message:
Sent: Mon November 03, 2025 03:24 AM
From: Hubert Heijkers
Subject: Error when attempting to create a hierarchy

Hi John,

Internally TM1 uses tab characters to separate hierarchy and element names in some cases. That tab character, AFAIK, is still the only 'metacharacter'. TM1 doesn't complain if you don't have alternate hierarchies, because it can't get confused until you do, but if you want to take advantage of alternate hierarchies you can no longer have tab characters in your element names or aliases, and that's what this error is trying to tell you.

------------------------------
Hubert Heijkers
STSM, Program Director TM1 Functional Database Technology and OData Evangelist
------------------------------