Dear Mubashir Majeed,

Based on the small code snippets you provided it's not easy to determine the cause of the error. However, as it seems that you are using RStudio you could try the 'trace back' button. Also it seems that other people ran into the same problem. The suggested solutions may help you as well:

http://stackoverflow.com/questions/22698581/performance-analytics-error-error-in-na-omit-xtsx-unsupported-type

http://r.789695.n4.nabble.com/na-omit-xts-unsupported-type-error-td3527676.html

Good luck!

Dear Mubashir contact Dr. M. Yasin in Stat Dept at Univ of Agri, Faislabad. Surely he will help you solve the problem.

Hello Mubashir,

As you have probably noticed from the other responses here, people usually cannot give you specific help if you don't post enough details about the problem you are having. Specifically, when the problem has to do with an error you're getting when running some code, it's always a good idea to post the relevant portion of your code and a description of your data; this makes it more likely you will be a helpful response.  For more guidelines on how to ask questions well, see http://journals.plos.org/ploscompbiol/article?id=10.1371/journal.pcbi.1002202 and http://www.fieldtriptoolbox.org/faq/how_to_ask_good_questions_to_the_community (the latter is for a specific software package, but the recommendations they make there apply pretty generally to any discussion group).