Does Microsoft CRM 2015 support your jscript?

I am getting a error in MS CRM 2015 for the jscript which uses the method"substr"

The only script which uses that method is in you cdi_jquery code.

<CrmScriptErrorReport>

<ReportVersion>1.0</ReportVersion>

<ScriptErrorDetails>

<Message>Object doesn't support property or method 'substr'</Message>

<Line>1</Line>

<URL>/_static/_controls/ribbon/ribbon.js?ver=754219076</URL>

<PageURL>/main.aspx#275577011</PageURL>

<Function>anonymousr:Objectdoesn'tsupportpropertyormethod'substr'</Function>

<FunctionRaw>TypeError: Object doesn't support property or method 'substr'</FunctionRaw>

<CallStack>

<Function>anonymousr:Objectdoesn'tsupportpropertyormethod'substr'</Function>

</CallStack>

</ScriptErrorDetails>

<ClientInformation>

<BrowserUserAgent>Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E)</BrowserUserAgent>

<BrowserLanguage>en-US</BrowserLanguage>

<SystemLanguage>en-US</SystemLanguage>

<UserLanguage>en-US</UserLanguage>

<ScreenResolution>1600x900</ScreenResolution>

<ClientName>Web</ClientName>

<ClienState>Online</ClienState>