Invalid viewstate dynamic controls

In asp.net web application, we are using dynamic controls in asp Table and other static controls.while navigating between forms or postabcks, We are facing an intermittent issue "Invalid Viewstate". Error Message:Invalid viewstate. Client IP: 27.251.48.180 Port: 8968 Referer: http://50.193.80.10/wfmtest/DailyErection.aspx Path: /wfmtest/DailyErection.aspx User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:39.0) Gecko/20100101 Firefox/39.0 ViewState: /wEPDwULLTEwOTMwMDU5MDYPZBYCZg9kFgICAw9kFgQCAw8PFgIeBFRleHQFEkJhcmNsYXkgRGF2aWQgVHJveWRkAhEPZBYCAgMPZBYCZg9kFhICAQ8PFgIfAAUKMDctMjgtMjAxNWRkAg0PE A8WBh4NRGF0YVRleHRGaWVsZAUHSm9iRGVzYx4ORGF0YVZhbHVlRmllbGQFA0pvYh4LXyFEYXRhQm91bmRnFgIeCG9uY2hhbmdlBQ9TaG93UHJvZ3Jlc3MoKTsQFbMBAA8wMS0wMDAgLSBvZm ZpY2UnMTItMTY1IC0gTm9ydGggJiBQdWxhc2tpIFNlbmlvciBIb3VzaW5nITEyLTE4NCAtIFNhbmdhbW9uIFRlcnJhY2UgU3IgQXB0cx8xMy0xMjggLSBWZXRlcmFucyBOZXcgQmVnaW5uaW5 nFDEzLTEzNyAtIFBpbm5hY2xlIDE2 ...