Hello, after an update to the newest version v2.45.170 I was asked to rebuild the index. So I did run the rebuild. Since then the system is not able to finish the index process. It always stops at 100%, but it is still running.
The WPFTS Pro version you are using is very outdated. Please consider upgrading to 2.46.x which is the latest. It has a completely new indexing and searching algorithm and it should solve your issue.