Mr FPS Hi and welcome
I recall Game Guru had changed the animation list for the fpsc classic characters. Every things there, just the order of anims has changed.
The original classic fpsc characters are still available at Github.... https://github.com/TheGameCreators/FPS-Creator-Classic
Also, a lot of the Game Guru characters had some of their bones moved/changed to reflect changes made in GG engine. You "Can" make them work, but a lot of extra work is needed.
For more info, come join us at Fpsc-Discord where most of the original Fpsc members have moved on to. Many can help you with these GG issues
** WHERE'S MY eXplosys ? **