Using the Firefox Plugin on MacOS, I cannot log into my WebDAV server any more. When trying to do so, I get an error message asking me to provide a password - which I did, and correctly. Strangely, synching file attachment works flawlessly with Zotero standalone, using the same WebDAV server and login credentials. It also used to work with the Firefox plugin, I have no idea why it stopped to do so. New Firefox version, upgrade to Mac OS Sierra? See also error report pasted in below .
Please help!
Stefan


(4)(+0000000): Registering observer for [collection,search,share,group,trash,bucket] in notifier with hash UG'

(3)(+0000024): TypeError: aId is undefined
===== Stack Trace =====
CustomizableUIInternal.isSpecialWidget@resource://app/modules/CustomizableUI.jsm:1237:5
CustomizableUIInternal.getWidgetProvider@resource://app/modules/CustomizableUI.jsm:858:9
CustomizableUIInternal.wrapWidget@resource://app/modules/CustomizableUI.jsm:469:20
this.CustomizableUI.createWidget@resource://app/modules/CustomizableUI.jsm:3263:12
@chrome://zotero/content/icon.js:119:1
ZoteroOverlay</this.onLoad@chrome://zotero/content/overlay.js:83:3
@chrome://zotero/content/overlay.js:285:47
Zotero_Preferences.openInViewer@chrome://zotero/content/preferences/preferences.js:122:6
Zotero_Preferences.Debug_Output.view@chrome://zotero/content/preferences/preferences_advanced.js:620:3
oncommand@chrome://zotero/content/preferences/preferences.xul:1:1
=======================

(4)(+0000012): Registering observer for [item-tag,setting] in notifier with hash 5v'

(3)(+0022747): Verifying storage

(3)(+0000000): Getting WebDAV password

(3)(+0000031): WebDAV password not provided

(3)(+0000002): [object Object] {
"message": "WebDAV password not provided"
"name": "Z_ERROR_NO_PASSWORD"
"filename": "webdav.js"
"toString": function {...}

}

(3)(+0001639): WebDAV verification failed

(4)(+0003771): Registering observer for [collection,search,share,group,trash,bucket] in notifier with hash f2'

(3)(+0000005): TypeError: aId is undefined
===== Stack Trace =====
CustomizableUIInternal.isSpecialWidget@resource://app/modules/CustomizableUI.jsm:1237:5
CustomizableUIInternal.getWidgetProvider@resource://app/modules/CustomizableUI.jsm:858:9
CustomizableUIInternal.wrapWidget@resource://app/modules/CustomizableUI.jsm:469:20
this.CustomizableUI.createWidget@resource://app/modules/CustomizableUI.jsm:3263:12
@chrome://zotero/content/icon.js:119:1
ZoteroOverlay</this.onLoad@chrome://zotero/content/overlay.js:83:3
@chrome://zotero/content/overlay.js:285:47
Zotero_Preferences.openInViewer@chrome://zotero/content/preferences/preferences.js:122:6
Zotero_Preferences.Debug_Output.view@chrome://zotero/content/preferences/preferences_advanced.js:620:3
oncommand@chrome://zotero/content/preferences/preferences.xul:1:1
=======================

(4)(+0000009): Registering observer for [item-tag,setting] in notifier with hash 4c'

(3)(+0037856): Verifying storage

(3)(+0000000): Getting WebDAV password

(3)(+0000034): WebDAV password not provided

(3)(+0000001): [object Object] {
"message": "WebDAV password not provided"
"name": "Z_ERROR_NO_PASSWORD"
"filename": "webdav.js"
"toString": function {...}

}

(3)(+0001835): WebDAV verification failed

(4)(+0009140): Registering observer for [collection,search,share,group,trash,bucket] in notifier with hash bm'

(3)(+0000005): TypeError: aId is undefined
===== Stack Trace =====
CustomizableUIInternal.isSpecialWidget@resource://app/modules/CustomizableUI.jsm:1237:5
CustomizableUIInternal.getWidgetProvider@resource://app/modules/CustomizableUI.jsm:858:9
CustomizableUIInternal.wrapWidget@resource://app/modules/CustomizableUI.jsm:469:20
this.CustomizableUI.createWidget@resource://app/modules/CustomizableUI.jsm:3263:12
@chrome://zotero/content/icon.js:119:1
ZoteroOverlay</this.onLoad@chrome://zotero/content/overlay.js:83:3
@chrome://zotero/content/overlay.js:285:47
Zotero_Preferences.openInViewer@chrome://zotero/content/preferences/preferences.js:122:6
Zotero_Preferences.Debug_Output.view@chrome://zotero/content/preferences/preferences_advanced.js:620:3
oncommand@chrome://zotero/content/preferences/preferences.xul:1:1
=======================

(4)(+0000010): Registering observer for [item-tag,setting] in notifier with hash Ok'