应该填finding.
这里涉及到一个知识点：have problem doing sth.做某事有问题
"have problem doing sth."与"have difficulty doing sth."都可表示某事存在一定的问题和困难.
I have some problems finishing this work.我完成这项工作有些问题.
Did your team have any problems winning the match?你们队赢这场比赛有什么问题吗?
I don't have any problems passing this exam.通过这次考试我没有问题.