I had this issue when I did the update to 2313, and now whit the update 2524 I have the same problem.
Not a big problem, PD has to build the shadow files again, but it is not correct I think.
How can I prevent PD to delete the shadow files when I update the program.
I had make a copie of the shadow files, but PD did not recognised the files, and build the shadowsfiles again.
Thanks
(Sorry for my poor english, but it isnot my native language) PC with Win10 Pro 64, Intel i7 2600 ,8 Gb Memory, Nvidia GeForce GTX 560 and a lot of Hard drives
Panasonic SD900 video camera