Tiles do not load - Connection Refused

[mcpicoli]

The problem: After using JOSM for a few minutes (many GPX layers, one data layer, one "Openstreetmap Carto" layer), the map layer stops loading tiles, and starts showing "Error downloading tiles: java.net.ConnectException: Connection refused: connect".

It usually "resets" to working status after several hours.

Before a few minutes of usage, everything is normal, everything loads and no errors are shown.

The console window is littered with hundreds (or thounsands) of java exceptions like this:

2019-10-21 11:38:58.775 INFO: GET https://b.tile.openstreetmap.org/18/97118/148792.png -> !!!
2019-10-21 11:38:58.775 WARNING: java.net.ConnectException: Connection refused: connect
java.net.ConnectException: Connection refused: connect
        at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method)
        at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:85)
        at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
        at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
        at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
        at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
        at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
        at java.net.Socket.connect(Socket.java:589)
        at sun.security.ssl.SSLSocketImpl.connect(SSLSocketImpl.java:673)
        at sun.net.NetworkClient.doConnect(NetworkClient.java:175)
        at sun.net.www.http.HttpClient.openServer(HttpClient.java:463)
        at sun.net.www.http.HttpClient.openServer(HttpClient.java:558)
        at sun.net.www.protocol.https.HttpsClient.<init>(HttpsClient.java:264)
        at sun.net.www.protocol.https.HttpsClient.New(HttpsClient.java:367)
        at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.getNewHttpClient(AbstractDelegateHttpsURLConnection.java:191)
        at sun.net.www.protocol.http.HttpURLConnection.plainConnect0(HttpURLConnection.java:1156)
        at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:1050)
        at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:177)
        at sun.net.www.protocol.https.HttpsURLConnectionImpl.connect(HttpsURLConnectionImpl.java:162)
        at org.openstreetmap.josm.tools.Http1Client.performConnection(Http1Client.java:77)
        at org.openstreetmap.josm.tools.HttpClient.connect(HttpClient.java:143)
        at org.openstreetmap.josm.tools.HttpClient.connect(HttpClient.java:123)
        at org.openstreetmap.josm.data.cache.JCSCachedTileLoaderJob.loadObject(JCSCachedTileLoaderJob.java:322)
        at org.openstreetmap.josm.data.cache.JCSCachedTileLoaderJob.run(JCSCachedTileLoaderJob.java:231)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
        at java.lang.Thread.run(Thread.java:748)

If the imagery is in the cache, after a few seconds, the error message clears and the cached tiles are shown.

While I know it is almost surely a network or tileserver problem, it started very recently after I upgraded from 15238 (or maybe 13367?). Maybe something changed in the current version that somehow triggers something at the tileserver that blocks connections?

Download/upload of data layers do not suffer from these effects.

Thanks.

Using version 15390.

[mcpicoli]

Sample image of the problem

[mcpicoli]

Sorry, forgot to say:

• Windows 10, latest update as of 2019-10-21
• java -version reports:

java version "1.8.0_171"
Java(TM) SE Runtime Environment (build 1.8.0_171-b11)
Java HotSpot(TM) 64-Bit Server VM (build 25.171-b11, mixed mode)