While you can download the installer, MDK-ARM requires a license for full functionality. Without a key, the software operates in Lite/Evaluation mode
Some older debug probes or third-party development boards have drivers that were optimized specifically for this release cycle. Conclusion
Projects created with Arm Compiler 5 (ARMCC) may not build with v5.25’s default Compiler 6. In Project → Options for Target → Target → Code Generation , change Use default compiler version 6 to Use Arm Compiler 5.06u7 (if legacy v5 compiler was installed separately). Note: v5.25 does not ship with v5 compiler by default – you must download ARMCC legacy pack.
