Failed to update the license file: unexpected end of JSON input

[Duplicacy Web edition 1.8.3, using CLI version 3.2.5]
Hello, last year I purchased a lifetime duplicacy license after a few years of yearly licenses. Everything was fine for a while, however I recently noticed that duplicacy had stopped running backups, and after investigating I discovered that the license seems to have been lost, the .duplicacy-web/licenses.json file is empty. I found the date of the last successful backup and then looked through the logs for that date. It looks like my server’s tmpfs ran out of space the previous day, which led to some job failures, but otherwise I don’t see any warnings before the server tries and fails to update the license:

 2026/06/11 01:49:01 Running /home/duplicacy/.duplicacy-web/bin/duplicacy_linux_x64_3.2.5 [-log prune -storage unraid-backup -keep 0:360 -keep 30:90 -keep 7:30 -keep 1:7 -threads 4 -a]                                
2026/06/11 01:49:01 Set current working directory to /cache/localhost/all                                                                                                                                              
2026/06/11 01:58:11 ERROR FOSSIL_COLLECT Failed to save the fossil collection file fossils/38: write /cache/localhost/all/.duplicacy/cache/unraid-backup/fossils/38.ycizjwpk.tmp: no space left on device              
2026/06/11 01:58:14 Schedule weekly-prune next run time: 2026-0613 01:49                                                                                                                                               
2026/06/11 11:00:02 Failed to save the schedule stats: write /home/duplicacy/.duplicacy-web/stats/schedules/daily-backup.stats: no space left on device                                                                
2026/06/11 11:00:03 Created log file /logs/backup-20260611-110003.log                                                                                                                                                  
2026/06/11 13:00:01 Starting schedule daily-check at scheduled time 2026-0611 13:00                                                                                                                                    
2026/06/11 13:00:01 Created log file /logs/check-20260611-130001.log                                                                                                                                                   
2026/06/11 13:00:01 Running /home/duplicacy/.duplicacy-web/bin/duplicacy_linux_x64_3.2.5 [-log check -storage unraid-backup -a -tabular]                                                                               
2026/06/11 13:00:01 Set current working directory to /cache/localhost/all                                                                                                                                              
2026/06/11 13:00:59 ERROR SNAPSHOT_CHECK Some chunks referenced by some snapshots do not exist in the storage                                                                                                          
2026/06/11 13:00:59 err: Some chunks referenced by some snapshots do not exist in the storage, exitCode: 100                                                                                                           
2026/06/11 13:01:02 Schedule daily-check next run time: 2026-0612 13:00                                                                                                                                                
2026/06/12 11:00:01 Starting schedule daily-backup at scheduled time 2026-0612 11:00                                                                                                                                   
2026/06/12 11:00:02 A new license has been downloaded for duplicacy-unraid                                                                                                                                             
2026/06/12 11:00:02 Failed to update the license file: unexpected end of JSON input                                                                                                                                    
2026/06/12 11:00:02 Failed to parse the stats file /home/duplicacy/.duplicacy-web/stats/schedules/daily-backup.stats: unexpected end of JSON input                                                                     
2026/06/12 11:00:02 A new license has been downloaded for duplicacy-unraid                                                                                                                                             
2026/06/12 11:00:02 Failed to update the license file: unexpected end of JSON input                                                                                                                                    
2026/06/12 11:00:02 Failed to parse the stats file /home/duplicacy/.duplicacy-web/stats/schedules/daily-backup.stats: unexpected end of JSON input                                                                     
2026/06/12 11:00:02 A new license has been downloaded for duplicacy-unraid                                                                                                                                             
2026/06/12 11:00:02 Failed to update the license file: unexpected end of JSON input                                                                                                                                    
2026/06/12 11:00:02 Failed to parse the stats file /home/duplicacy/.duplicacy-web/stats/schedules/daily-backup.stats: unexpected end of JSON input                                                                     
2026/06/12 11:00:02 A new license has been downloaded for duplicacy-unraid                                                                                                                                             
2026/06/12 11:00:02 Failed to update the license file: unexpected end of JSON input 

Once I found this, I tried to manually refresh the license from the GUI using the activation code that I got when I purchased the license. Unfortunately I get the same “unexpected end of JSON input” error. On the duplicacy dashboard I see that the license says that is still connected to this duplicacy instance on this server. Should I do a complete re-install of duplicacy, and use the dialog at the duplicacy license webpage to transfer the license? Or is there anything else I can try? Thanks

Just delete the licenses.json file and reactivate via the GUI.

Duplicacy Web doesn’t deal so well with 0-byte .json files - you might notice more of them in the .duplicacy-web\stats\schedules and .duplicacy-web\stats\storages folders - if you ran out of space. So you’ll need to delete any 0-byte files from there as well (for the stats to work).

Also, if your Duplicacy storage was on the same disk - you’ll want to make sure there’s no 0-byte chunks or snapshots too.