This is almost always due to improper JSON formatting. Check the SlayTheSpire/sendToDevs/logs/SlayTheSpire.log file for error messages—it will tell you exactly which line has the formatting issue.
Here is the complete guide to unlocking everything in Slay the Spire on Android, ranging from legitimate fast-farming strategies to quick file-editing workarounds. Method 1: The Quick File Editing Glitch (No Root Required) slay the spire android unlock everything
To maximize score accumulation and unlock cards and relics faster: This is almost always due to improper JSON formatting