Praise be to Allaah.
There is no evidence as far as I know to say that it is permissible to join ‘Asr to Jumu’ah prayer. That was not narrated from the Prophet (peace and blessings of Allaah be upon him) or from any of his companions (may Allaah be pleased with them), so we should not do that. The one who did that should repeat ‘Asr prayer when the time for it comes. May Allaah help us all.