Known issues
Regarding FolderSync 2.9.x
It seems a fair amount of users have experienced issues with the latest releases. There has been a major rewrite of the back end HTTP layer, but unfortunately a lot issues seems to have not been ironed out during the beta phase.

Here are some notes about common problems reported:
  • Dropbox/OneDrive/Google Drive bad request or failing folderpairs - please try to re-authenticate account. In some cases you also need to re-select to remote folder for folderpairs, since the path structure on the remote end has changed because of usages of new API versions. Just re-select the folder you are already using, so the remote folder info can be refreshed.
  • OwnCloud connections issues may be caused by streamlining of the configuration into two account types for ownCloud 6/7 and 8 respectively. Please reconfigure your accounts accordingly. If you get something like "refused stream" error for HTTP/2 you need to upgrade to latest nginx web server and version 2.9.4, where this is fixed.
  • OwnCloud upload issues  may be caused by incomplete account configuration. Make sure you specify the correct protocol in server name field, either HTTP or HTTPS - this should match the server endpoint. If your server redirects HTTP to HTTPS, this will not always work for uploads for example, so make sure this configured correctly.
  • Authentication using OAuth was reworked to be done in a custom Chrome tab by default. This worked great on our test devices, but some users have experienced issues. It is now disabled by default, but can be re-enabled in settings if you want that extra bit of security.
  • Sync speed issues - some have experienced slower sync times, this should be fixed in version 2.9.4 where you should actually get faster syncs than previously.
  • OneDrive upload timeouts - a few people have report issues uploading files to OneDrive, this should be working as of 2.9.4 at least judging by user feedback.
  • HTTP connection errors can happen on newer Android devices, since deprecated encryption ciphers are no longer enabled by default with OkHttp/Android to increase security. This means, if you are connecting to an insecure web server using WebDAV or ownCloud, the connection may fail. You can either upgrade your server or try to enable self-signed certificates for you WebDAV/ownCloud account. Se here which protocols/ciphers are supported on which Android versions:
If you experience any serious new issue not mentioned above, feel free to send a log file using the guide below with a explanation of the problem.

External SD card write
Writing to External SD card on Android 5.x and later - see here.

Have a suggestion?
To vote for or create new feature requests go here: Feature requests

What to do if you need help
Try reading the help page and FAQ for the product - there are a lot of answers there. 
Also try searching this site using the search field at top right.

FolderSync:  Help, FAQ, Known issues

Community help
You can also try to visit the FolderSync Google+ community, the CloudCaster Google+ community  or search the old locked forum and make your issue known or put forward your request. They have separate search functions - please try 
them first, to see if your query has already been answered, before posting new questions.

Report bug
Bugs cant be report to the bug tracker found here: 

Request refund or transfer of license
If you want to request a refund with a 72 hour after purchase or transfer your license to another Google account fill out this form:

The technical stuff
If you  have a specific problem with an app, then please include a log file using the procedure below.
Please only send log files if requested by us.

How to create and send a log file
  1. To create a log file with useful data, enable [Collect logs] on our app's about screen.
  2. Redo the function/action that fails (previous errors will not be logged, so this step is important).
  3. Go back to the about screen and review the log if you want.
  4. Then press [Send collected logs] to attach the log to a new e-mail.
  5. Add your description of the problem and press send. Log files received without an error description are deleted.
Just as a disclaimer, we can unfortunately not promise to answer all support requests in a timely manner.