This error occurs when definition is modified with #, but the original description of it, does not exist.
Ensure that the original description exists or check whether # is used in the definition name by mistake.
Example
[#Field: NaemField]
Width: 10 mms
In the above example the field NaemField is modified with #, but its original description doesn't exist. Hence the error message error T0008: Could not find the original description for Field - NaemField appears.
Since the definition name was misspelt, the code is corrected as shown below:
[#Field: NameField]
Width: 10 mms