The is a Dynamic Link Library (DLL) file. DLL files are shared sets of instructions that different programs call upon to perform specific tasks.
A failed update or improper shutdown can corrupt the file. Steam-api64r.dll File Download
Before downloading anything, check if your antivirus software has simply hidden the file. Open or your third-party antivirus. Navigate to Protection History or Quarantine . The is a Dynamic Link Library (DLL) file
Security software often flags these DLL files as "false positives" and moves them to quarantine, especially if they have been modified. especially if they have been modified.