I had to replace the MB of my PC. Since that time, I've run into this issue while trying to update one of my galleries.

One of the things I've tried is Make Album a couple of times. I also deleted the "old" web store and recreated that from scratch. But every time I try and upload to my server I get this message. (It also happens on different "slides")

info.cqs.remotefs.RemoteFSException: Error uploading Gigglefly 12-07-2018-403.webp to /GiggleFly/Darkroom Gigglefly/slides/Gigglefly 12-07-2018-403.webp:
at info.cqs.remotefs.RemoteFSBean.putFile(RemoteFSBean.java:397)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(Unknown Source)
at java.base/java.lang.reflect.Method.invoke(Unknown Source)
at info.cqs.remotefs.RemoteFSBean$RemoteFSHandler.invoke(RemoteFSBean.java:520)
at jdk.proxy2/jdk.proxy2.$Proxy12.putFile(Unknown Source)
at se.datadosen.jalbum.UploadBean.lambda$uploadFilesImpl$2(UploadBean.java:221)
at se.datadosen.jalbum.RemoteFSWorkers$2.call(RemoteFSWorkers.java:190)
at se.datadosen.jalbum.RemoteFSWorkers$RemoteCallable.call(RemoteFSWorkers.java:392)
at java.base/java.util.concurrent.FutureTask.run(Unknown Source)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.base/java.lang.Thread.run(Unknown Source)
Caused by: info.cqs.remotefs.RemoteFSException: it.sauronsoftware.ftp4j.FTPException http://code=426, message= Transfer aborted. Data connection closed
at info.cqs.remotefs.ftp.Ftp4jAdapter.putFile(Ftp4jAdapter.java:402)
at info.cqs.remotefs.RemoteFSBean.putFile(RemoteFSBean.java:394)
... 11 more
Caused by: it.sauronsoftware.ftp4j.FTPException http://code=426, message= Transfer aborted. Data connection closed
at it.sauronsoftware.ftp4j.FTPClient.upload(FTPClient.java:2619)
at info.cqs.remotefs.ftp.Ftp4jAdapter.putFile(Ftp4jAdapter.java:392)
... 12 more

Try switching to one of the other protocols. The most robust option, if your web host supports it, is SFTP.

If it's your own web server, reconfigure it to enable SFTP connection.

Not to put too fine a point on it, but if you don't know how to do that, perhaps you should think about getting a regular web host - SFTP uploading is fairly standard these days, even on bargain hosts. And in my experience, it's far less susceptible to weird, intermittent failures.