Error message

pDF files will no longer open on my android.  Error says "File corrupt or Filename too long".  I have tried several different files online and every .pdf has the same error.  I am using a Samsung Galaxy 10 plus with android 11 and recently swapped out my Sprint sd card for the new t-mobile card.....being unable to open newly downloaded pdf's is extremely frustrating, how can I fix this problem?  I cant even find the "downloaded" pdf file....