diff --git a/start.sh b/start.sh
index 55adb80..f1e8f45 100644
--- a/start.sh
+++ b/start.sh
@@ -315,25 +315,20 @@ if [ -x "$(command -v go)" ]; then
         REQUIRED_VERSION=$(grep -o "go [0-9]\+\.[0-9]\+" "$SERVER_DIR/go.mod" | cut -d " " -f 2)
         echo "==> Required Go version: $REQUIRED_VERSION"
         
-        # Always update go.mod to use a known compatible version
-        echo "==> Setting go.mod to use Go 1.20 for better compatibility"
-        sed -i "s/go [0-9]\+\.[0-9]\+/go 1.20/" "$SERVER_DIR/go.mod"
-        echo "==> Updated go.mod to use Go 1.20"
-        
-        # Print the modified go.mod for debugging
-        echo "==> Modified go.mod contents:"
-        cat "$SERVER_DIR/go.mod" | head -5
+        # Don't try to modify the go.mod file since filesystem is read-only
+        # Instead, use environment variables to override version requirements
+        echo "==> Setting Go flags to override version requirements"
+        export GOFLAGS="-mod=mod"
+        export GO111MODULE=on
+        export GOTOOLCHAIN=local
     fi
 else
     echo "==> Installing Go"
     apt-get update && apt-get install -y golang
 fi
 
-# Install Go binaries for fixed versions
-echo "==> Ensuring compatible Go version is available"
-go install golang.org/dl/go1.20@latest
-echo "==> Installed go1.20 download tool"
-$GOPATH/bin/go1.20 download || echo "==> Note: Could not download go1.20 - will use system version"
+# Skip trying to install specific Go versions since we can't modify /app/code
+echo "==> Using existing Go toolchain with compatibility flags"
 
 # Check for libsodium
 if dpkg -l | grep -q libsodium; then
@@ -357,11 +352,13 @@ cd "$SERVER_DIR"
 # Set Go module cache to a writable location
 export GOPATH=/app/data/go
 export GO111MODULE=on
-# Allow Go to use the current version
-# Change these settings to fix the toolchain availability issue
-export GOTOOLCHAIN=local  # Don't try to download new toolchains
-# export GOPROXY=direct    # This can cause issues, so let's use the default
-echo "==> Using existing Go toolchain, disabled auto-downloading"
+# Set version compatibility flags
+export GOTOOLCHAIN=local
+# Create a temporary directory for Go module cache and build in writable area
+export GOCACHE=/app/data/go/cache
+export GOMODCACHE=/app/data/go/modcache
+mkdir -p $GOCACHE $GOMODCACHE
+echo "==> Set up Go environment in writable directories"
 
 # Set up more verbose logging for API debugging
 export ENTE_LOG_LEVEL=debug
@@ -432,21 +429,10 @@ elif [ -d "$SERVER_DIR/cmd/museum" ]; then
     echo "==> Found Museum source in cmd/museum, running with go run"
     cd "$SERVER_DIR"
     
-    # Check go.mod and explicitly modify it to use a compatible Go version
-    if [ -f "$SERVER_DIR/go.mod" ]; then
-        echo "==> Checking go.mod for version requirements"
-        GO_VERSION=$(go version | cut -d " " -f 3 | sed 's/go//')
-        echo "==> System Go version: $GO_VERSION"
-        
-        # Force go.mod to use a compatible version
-        echo "==> Setting go.mod to use Go 1.20"
-        sed -i "s/go 1\.[0-9]\+/go 1.20/" "$SERVER_DIR/go.mod"
-        echo "==> Updated go.mod to use Go 1.20"
-        
-        # Print the modified go.mod for debugging
-        echo "==> Modified go.mod contents:"
-        cat "$SERVER_DIR/go.mod" | head -5
-    fi
+    # Instead of modifying go.mod, set environment variables for compatibility
+    echo "==> Setting Go environment variables for compatibility"
+    export GOFLAGS="-mod=mod"
+    export GOTOOLCHAIN=local
     
     # For Wasabi specific settings
     if [[ "${S3_ENDPOINT}" == *"wasabi"* ]]; then
@@ -521,25 +507,10 @@ else
         echo "==> Using main.go file at $MAIN_FILE"
         cd "$MAIN_DIR"
         
-        # Check for go.mod in this directory
-        GO_MOD_DIR=$(find "$(dirname "$MAIN_DIR")" -name "go.mod" | head -1 || echo "")
-        if [ -n "$GO_MOD_DIR" ]; then
-            GO_MOD_DIR=$(dirname "$GO_MOD_DIR")
-            echo "==> Found go.mod in $GO_MOD_DIR"
-            cd "$GO_MOD_DIR"
-            
-            # Modify go.mod to use a compatible Go version
-            echo "==> Setting go.mod to use Go 1.20"
-            sed -i "s/go 1\.[0-9]\+/go 1.20/" "go.mod"
-            echo "==> Updated go.mod to use Go 1.20"
-            
-            # Print the modified go.mod for debugging
-            echo "==> Modified go.mod contents:"
-            cat "go.mod" | head -5
-            
-            # Change back to main directory
-            cd "$MAIN_DIR"
-        fi
+        # Instead of trying to modify go.mod, set environment variables for compatibility
+        echo "==> Setting Go environment variables for compatibility"
+        export GOFLAGS="-mod=mod"
+        export GOTOOLCHAIN=local
         
         echo "==> Running main.go with Go"
         /usr/local/bin/gosu cloudron:cloudron go run main.go --port 8000 \
@@ -588,7 +559,6 @@ import (
     "log"
     "net/http"
     "os"
-    "io/ioutil"
 )
 
 func main() {
@@ -600,7 +570,7 @@ func main() {
         
         // Show log excerpts if available
         if _, err := os.Stat("/app/data/logs/museum-server.log"); err == nil {
-            logs, err := ioutil.ReadFile("/app/data/logs/museum-server.log")
+            logs, err := os.ReadFile("/app/data/logs/museum-server.log")
             if err == nil && len(logs) > 0 {
                 fmt.Fprintf(w, "<h2>Recent Log Output:</h2><pre>%s</pre>", logs)
             }
@@ -622,6 +592,11 @@ func main() {
 }
 EOT
     cd /tmp/mock-server
+    
+    # Set Go environment variables for compatibility with the mock server
+    export GOFLAGS="-mod=mod"
+    export GOTOOLCHAIN=local
+    
     go run main.go &
     SERVER_PID=$!
     echo "==> Mock server started with PID $SERVER_PID to show error message"