The b1531b115956bc02
in that error message is the ID of an editor tab.
It would be useful to see an export of that tab too.
There may be a simple way to get the tab name (the "label" property) from the ID but I'm not aware how, so here is a flow to extract it from the flows file (you might need to change the flows file pathname)
[{"id":"e354973541e14b65","type":"inject","z":"e56de693d0e0a509","name":"","props":[{"p":"payload"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"b1531b115956bc02","payloadType":"str","x":210,"y":100,"wires":[["4cf75cfcb9feb511"]]},{"id":"f3fdbbee199ddbdd","type":"file in","z":"e56de693d0e0a509","name":"","filename":".node-red/flows.json","filenameType":"str","format":"utf8","chunk":false,"sendError":false,"encoding":"none","allProps":false,"x":200,"y":160,"wires":[["9a585a43f3963148"]]},{"id":"59168d428a3de93c","type":"switch","z":"e56de693d0e0a509","name":"","property":"payload.id","propertyType":"msg","rules":[{"t":"eq","v":"chosenNodeId","vt":"flow"}],"checkall":"true","repair":false,"outputs":1,"x":290,"y":220,"wires":[["bc7fbdf1c70efe94"]]},{"id":"9a585a43f3963148","type":"json","z":"e56de693d0e0a509","name":"","property":"payload","action":"","pretty":false,"x":490,"y":160,"wires":[["43b49091765ec263"]]},{"id":"bc7fbdf1c70efe94","type":"debug","z":"e56de693d0e0a509","name":"debug 115","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","statusVal":"","statusType":"auto","x":450,"y":220,"wires":[]},{"id":"43b49091765ec263","type":"split","z":"e56de693d0e0a509","name":"","splt":"\\n","spltType":"str","arraySplt":1,"arraySpltType":"len","stream":false,"addname":"","x":150,"y":220,"wires":[["59168d428a3de93c"]]},{"id":"4cf75cfcb9feb511","type":"change","z":"e56de693d0e0a509","name":"","rules":[{"t":"set","p":"chosenNodeID","pt":"flow","to":"","tot":"str"}],"action":"","property":"","from":"","to":"","reg":false,"x":440,"y":100,"wires":[["f3fdbbee199ddbdd"]]}]
Can you show us what is on that editor tab? A screen capture would help but an export is always better.