Customfield updateValue class cast exception String cannot be cast to Option Edited

[Komail Badami]

I have a radio button field whose value I am updating during issue creation which is fetched from a workflow transition screen, but I end up getting the below exception

java.lang.ClassCastException: java.lang.String cannot be cast to com.atlassian.jira.issue.customfields.option.Option

Below is the code

FieldLayoutItem fieldLayoutItem = ComponentAccessor.getFieldLayoutManager().getFieldLayout(issue)
.getFieldLayoutItem(customField);

DefaultIssueChangeHolder issueChangeHolder = new DefaultIssueChangeHolder();

CustomField customField = ComponentAccessor.getCustomFieldManager().getCustomFieldObject(customFieldId);

CustomFieldManager  custFieldMgr = ComponentAccessor.getCustomFieldManager();

<--Get the value which was set in the radio button-->
Option optionValue = (Option)mIssue.getCustomFieldValue(custFieldMgr.getCustomFieldObject("customfield_" + customFieldId));

System.out.println("Option value "+optionValue.getValue());

issue.setCustomFieldValue(customField, optionValue.getValue());

ModifiedValue modifiedValue =  new ModifiedValue("", optionValue.getValue());

customField.updateValue(fieldLayoutItem, issue, modifiedValue, issueChangeHolder);

 How can I resolve this issue , I am able to get the values set in the customfield but due to this cannot update the values when the issue is created.