Which version of LabVIEW are you having this issue with and is it on a fresh install? Before reinstalling LabVIEW, have you tried to 'Repair' the current installation?
To Repair your installation go to Control Panel >> Add/Remove Programs >> National Instruments Software >> Change >> Select your LabVIEW version >> Select Repair.
Do you have any other background information regarding this issue? Can you reproduce the broken run arrow by creating a blank VI and creating a Match Regular Expression node?
Let me know what you find. Cheers!