OnBase 18. Error when Unity script AddKeyword to the multi page document

[Gregory_Moldavs]

OnBase18 Task use Unity Project which add/update one Keyword.

keyModifier.AddKeyword(kName, kValue);

or

keyModifier.UpdateKeyword(addKeyword, newKeyword);

It is working when tif document has only one page.

Not working when tif document has several pages. 

Error: "Keywords can only be modified on an active document".

Old VBScript is working OK.

Any solution?

[Gregory_Moldavs · Accepted solution]

Problem solved.

It was on test environment. When I load new document for testing, it works.