OLE error

I've created a spreadsheet for around six colleagues to use, which contains a large number of hyperlinks to documents (Word and pdfs) held in a related folder structure. There is one copy of the spreadsheet only (as it is being frequently updated by me) and its opens as 'read-only' for the other users. However, there is a recurring problem in that it freezes sometimes when a user clicks a hypoerlink, and a message appears that 'another OLE process is running and not completed'. At this point the Excel seesion needs to be killed by our IT support. Any idea, please why, this problem is occuring, and how it can be resolved?