sstableexpiredblockers can throw FileNotFound exceptions

Exception in thread "main" java.lang.RuntimeException: java.io.FileNotFoundException: /path/to/data/system/sstable_activity/system-sstable_activity-jb-85002-Data.db (No such file or directory)
at org.apache.cassandra.io.compress.CompressedRandomAccessReader.open(CompressedRandomAccessReader.java:47)
at org.apache.cassandra.io.util.CompressedPoolingSegmentedFile.createReader(CompressedPoolingSegmentedFile.java:48)
at org.apache.cassandra.io.util.PoolingSegmentedFile.getSegment(PoolingSegmentedFile.java:39)
at org.apache.cassandra.io.sstable.SSTableReader.getFileDataInput(SSTableReader.java:1242)
at org.apache.cassandra.db.columniterator.SimpleSliceReader.<init>(SimpleSliceReader.java:57)
at org.apache.cassandra.db.columniterator.SSTableSliceIterator.createReader(SSTableSliceIterator.java:65)
at org.apache.cassandra.db.columniterator.SSTableSliceIterator.<init>(SSTableSliceIterator.java:42)
at org.apache.cassandra.db.filter.SliceQueryFilter.getSSTableColumnIterator(SliceQueryFilter.java:173)
at org.apache.cassandra.db.filter.QueryFilter.getSSTableColumnIterator(QueryFilter.java:62)
at org.apache.cassandra.db.CollationController.collectAllData(CollationController.java:250)
at org.apache.cassandra.db.CollationController.getTopLevelColumns(CollationController.java:53)
at org.apache.cassandra.db.ColumnFamilyStore.getTopLevelColumns(ColumnFamilyStore.java:1599)
at org.apache.cassandra.db.ColumnFamilyStore.getColumnFamily(ColumnFamilyStore.java:1418)
at org.apache.cassandra.db.Keyspace.getRow(Keyspace.java:330)
at org.apache.cassandra.db.SliceFromReadCommand.getRow(SliceFromReadCommand.java:65)
at org.apache.cassandra.cql3.statements.SelectStatement.readLocally(SelectStatement.java:296)
at org.apache.cassandra.cql3.statements.SelectStatement.executeInternal(SelectStatement.java:315)
at org.apache.cassandra.cql3.statements.SelectStatement.executeInternal(SelectStatement.java:64)
at org.apache.cassandra.cql3.QueryProcessor.processInternal(QueryProcessor.java:208)
at org.apache.cassandra.db.SystemKeyspace.getSSTableReadMeter(SystemKeyspace.java:957)
at org.apache.cassandra.io.sstable.SSTableReader.<init>(SSTableReader.java:340)
at org.apache.cassandra.io.sstable.SSTableReader.open(SSTableReader.java:196)
at org.apache.cassandra.io.sstable.SSTableReader.open(SSTableReader.java:184)
at org.apache.cassandra.io.sstable.SSTableReader.open(SSTableReader.java:150)
at org.apache.cassandra.io.sstable.SSTableReader.open(SSTableReader.java:142)
at org.apache.cassandra.tools.SSTableExpiredBlockers.main(SSTableExpiredBlockers.java:77)