Receiving 'Element is using storage alias' error when attempting to change dictionary column type

[Troy S_]

I have 2 custom fields that I need to change from a string to HTML.   However every time I attempt this I get the following error "Element is using storage alias.   Cannot modify this element's type because it shares a storage alias:[task.u_test shared with 2 total element(s)].   I was able to change a couple of them that where not custom fields.   I know there is a work around, but I do not/cannot delete it and rebuild it as it contains information that is still needed for past changes.

Thank You in advanced

Troy

[Chuck Tomasi · Accepted solution]

Hi Troy

This is due to a feature in the platform known as task flattening. This was put in place in Dublin as a performance enhancement at runtime. Several string fields on various tables are using the same physical database field to store information. As a result, you cannot change your field type because it would impact the other fields.

Your best bet is to create a new field of type HTML and migrate your information from the string field to the HTML field (if you wish to preserve the content.)

[Troy S_]

Thank you for the quick response, and information.   Was not the answer I was hoping to hear, but I will proceed with your suggestion.  

[Chuck Tomasi]

You are welcome. Normally table flattening is pretty transparent to people. FWIW, changing field types always carries with it a risk. String to HTML is pretty low, but in this case because of the aliases to the other fields, it's blocked.

Let us know if you need additional help.

[SC10]

Is this the same reason that a Date/Time field can't be changed into a Date field? It's something that I've tried to do lately, but I also got an error of "Element is using storage alias" which caught me off guard, and still don't fully understand.