EndoNote X1 crash after clicking online search


I am running OX 10.5.7 on my MacBook Pro with EndNote X1 installed. I used to be able to run the EndNote X1 perfectly until recently. Now, I can not do any online search anymore no matter what library catalog I select (e.g. PubMed). I thought about the possible corruption of the connection files, so I downloaded the new connection files for PubMed from EndNote web site and replaced the old ones with the newly downloaded ones. The problem persists. Every time I click on the preselected database (e.g. PubMed or other database) for a online search for new references, EndNote program simply stops and crash. Any idea? It looks like it is not caused by a corrupted connection file, but more like a general problem existing in the program itself. Is there any update that can fix this type of crash?  In addition, would this be related to opening a Window-generated EndNote library in a Mac computer? Right now, I am working on 2 Window-generated EndNote libraries. The crash seems to occur after I converted those into Mac libs. I can still open the libraries, but no online search at all. I can still create a new Mac EndNote library, but again clicking online search causes the crash. Thank you very much for your help!!!