The two products are unable to generate reports when installed on same machine. Install Sage Fixed Assets onto a separate machine (VM is possible).
Crystal workaround: Starting with SAP ® Crystal Reports runtimes SP21 (13.0.21) and higher, it is possible to create a .exe.config. This has the effect of redirecting the program to use older Crystal libraries contained in the SAP ® Crystal Reports runtimes SP21.
Contact the 3rd party application vendor support about the .exe.config file option.